With our shift to remote learning, I'll be (valiantly attempting) to orchestrate my courses using Google Classroom. Students, you should have already received an invitation via your Profile e-mail account. The adventure begins!

Friday, March 13, 2020

1.) HW Check-in. (#22 and 24 on p.330. )

2.) Tailpipe problem. How much carbon dioxide is emitted from the tailpipe of YOUR car during a roundtrip commute from YOUR house to school and back? Is it teeny-weeny? How much, really?

HW: Try to do this without looking back at the work you did today. If you're REALLY stuck, then, of course, take a peak.

A 2013 Kia Sorento V6 (that is, its the model with the 6 cylinder engine) makes a trip from Bethlehem, NH to Anchorage, AL.

Assuming that we model the combustion of gasoline in the cylinders as the complete combustion of octane (C8H18), how many POUNDS of carbon dioxide are emitted from the tailpipe during the trip? Yes, you'll need to find out about the gas mileage of the Sorento and the distance from Bethlehem to Anchorage.

Wednesday, March 11, 2020

1.) INTRO to...........What's coming out of YOUR tailpipe ?!?!?!?! <YAR> <YAR> <YAR>

A sweet stoichiometry problem involving estimating how many pounds (?!) of carbon dioxide is emitted from your car's tailpipe when you drive to and from school from your house. What car do you usually drive? What's its gas mileage?

http://www.animatedengines.com/otto.html (4-stroke internal combustion engine)

2.) More reaction stoichiometry: working up to mass-mass problems. (DIDN'T GET TO THIS TODAY)

3.) Part 1: What's coming out of YOUR tailpipe ?!?!?!?! Gather the info you need. Maybe look up your car's gas mileage. Find the distance from your house to school (then double it). Maybe use mapquest. The school's address is 691 Profile Road, Bethlehem, NH 03574

HW: 1.) Go up to a car that is running. Squint really hard and stare at the exhaust pipe. Point and insist you can see the carbon dioxide spewing out.

2.) Find the # of miles from your house to school (691 Profile Rd, Bethlehem, NH 03574) and double it for the round-trip distance. Then, find out the gas mileage for your car. Either because you and/or your family keep track of it, or by looking up your make and model of car and finding out the reported value.

3.) Stoichiometry problems: #22 and 24 on p.330. PLEASE don't just "sort of" try these. Make use of the indicated example problems back in the chapter. Also, we did example problems similar to these in class.

Monday, March 9, 2020

1.) Check-in and some hints about balancing chemical reactions.

2.) More reaction stoichiometry: working up to mass-mass problems. (DIDN'T GET TO THIS TODAY)

HW:

1.) Do the next 8 balancing chemical reactions problems. Just need to practice these. Eventually they get easy.

Wednesday, March 4, 2020

1.) Heads up. Test next class.

2.) Reaction Stoichiometry. So, how is the amount of one substance in a chemical reaction related to the amount of another substance involved in the reaction?

*What does it mean to "balance a chemical reaction"? (really just a version of Conservation of Mass)

*Mole-mole, mass-mole, mass-mass calculation progression

3.) Workshop: Help preparing for the Test on Friday

HW: 1.) Balance the first 8 chemical reactions on the "Balancing Equations Race" handout. We'll reveal some handy tricks/approaches next time, but let's see what you try or notice yourself first.

2.) Test next class: Stoichiometry #1 (particles-moles-mass conversions, molar mass, percent composition, average atomic mass calculations (weighted average), empirical formulas, molecular formulas, solutions and concentration). So finish up your prep by seeking and practicing problems that YOU need to work on. The study guide should be helpful.

Monday, March 2, 2020

1.) Heads up: Test on Friday. Topics: Conversions (grams/moles/# of particles), making solutions, % composition, empirical formula problems, finding molecular formulas knowing % composition and the molar mass, average atomic mass problems. (So, the basic stoichiometry-ish skills we've been working on that last few weeks).

2.) Workshop: Let's work on the stoichiometry-type problems we've gotten to know about.

HW: 1.) Test on Wednesday. Topics: Conversions (grams/moles/# of particles), making solutions, % composition, empirical formula problems, finding molecular formulas knowing % composition and the molar mass, average atomic mass problems. (So, the basic stoichiometry-ish skills we've been working on that last few weeks).

2.) Use the study guide to choose and practice particular types of problems to practice to prepare for the test.

Winter Carnival and Winter Vacation !

Wednesday, February 19, 2020

1.) OK, a workshop/consolidation/finish stuff up day.

2.) First: Finish the Solutions Lab and the corresponding #9-#11 problems.

3.) Workshop: Anything we've been working on the last couple weeks.

HW: Catch up, as necessary.

Monday, February 17, 2020

1.) Last new idea in this first bundle of stoichiometry skills: Finding empirical formulas from percent composition. Also, finding the actual formula if you know the molar mass.

Handy poem to help you find empirical formulas from percent composition.

Percent to mass,

Mass to mole,

Divide by small,

Multiply 'til whole (if needed).

2.) Open workshop: Main events - finish the solutions lab; review the #9-#11 solutions HW problems. Secondary events - helping each other out with any of the other recent skills we've been working on (conversions between particles-moles-grams, for example)

HW: 1.) #25, 33, 39, 43, 48, 54, 55, 61 on pp. 252-254. (Yes, make use of the sample problems to help, if needed!)

Friday, February 14, 2020

1.) Average Atomic Mass (a weighted average)

* Average atomic mass (a weighted average of an element's isotopes)

2.) Percent Composition (Hmmm....by volume? By number? By mass? Which one?)

* Percent Composition is just the percentage (by mass) of each element in a compound.

3.) Lab: Solutions........finish this up.

4.) Workshop on solutions and concentrations problems.

HW: 1.) Read pp. 234-235. Sample problem E ! Practice Problems #1-2 on p.236.

2.) Read p. 241. Then read Sample Problem I on p.247. Practice Problems #1, 3 on p.248.

Wednesday, February 12, 2020

1.) Quick on-the-board HW workshop.

2.) Lab: Making solutions. And more experience with molarity.

HW: 1.) Do the 3 "Some solution problems" (#9-11) from the handout in class.

2.) Finish/refine the #particle - #moles - # of grams conversion problems. (The mob of problems from the HW a few classes ago.) if you haven't done so already for any reason.

Monday, February 10, 2020

1.) Intro. to concentration of solutions. There are lots of ways to specify the concentration of a solution. A very common one in chemistry is molarity, which is the number of moles of solute per liter of solution (moles/Liter, or molar, M) . A solution with a concentration of 3moles/Liter is 3M or "3 molar" solution.

2.) Workshop: #Particles - #Moles - #Grams conversions.

HW: 1.) How many moles of NaCl would you need to make 5 Liters of a 2M solution?

2.) So, how many grams of NaCl would you need to measure out make the solution in #1?

3.) Find the concentration (molarity ) of a solution that contains 2.3 moles of NaOH in 0.9 Liters of water.

4.) You dissolve 78g of NaOH in 2.5 Liters of water. What is the molarity of the solution? That is, what is its concentration in moles/L?

Friday, February 7, 2020

***SNOW DAY ! ***

Wednesday, February 5, 2020

1.) Hey, I didn't make this.... https://www.youtube.com/watch?v=PvT51M0ek5c

2.) Handy little diagram... # of particles ----#of moles ------# of grams

3.) Some actual substances. How much of them is needed to have a mole of each? If we have a random amount of one of these substances, how many moles or particles are in the sample?

4.) Workshop: Start on the Particles-Moles-Grams HW problems, or check-in about the previous HW if needed

HW: Finish the Particle-Moles-Grams practice problems we started in class. Folks, just need to practice these. They started out VERY unfamiliar. Now, they are getting reasonably familiar.

Monday, February 3, 2020

1.) Reminder of what a mole is and how we now can use the "average atomic mass" on the periodic table in a very handy, practical way.

2.) # of particles --------------# of moles ----------------# of grams

Conversions between these 3 ways of specifiying an amount of a substance.

3.) Workshop: HW problems (p.233)

HW:

1.) Read and check out the example problems on pp. 230-233.

2.) Problems. pg. 233, the "b"s of #6-13. Use the example problems on the previous pages to help you, as needed.

Friday, January 31, 2020

1.) Intro to stoichiometry, which is the chemistry of AMOUNTS.

2.) What's mole? Why this number? Why is this useful?

OK, what's the deal with this particular number......6.022*10^23? Why THIS number?

*Connection between the average atomic mass on the periodic table, a mole of that material, and how many grams one mole of it would be.

*1 amu (atomic mass unit) = 1.66054*10^-24 grams and how is an amu defined?

*mass of a proton = 1.007276 u (u is for amu, like N is for Newtons....)

*mass of a neutron = 1.008664 u

3.) Example problems: Molar mass, and converting from grams to moles and vice versa.

HW:

1.) Read and check out the example problems on pp. 230-233.

2.) Problems. pg. 233, the "b"s of #6-13. Use the example problems on the previous pages to help you, as needed.

Wednesday, January 29, 2020

1.) Hand in your practice tests.

2.) Test. Topics: VSEPR, polarity of bonds, polarity of molecules, IMFs and how they affect the properties of substances, hydrogen bonding IMF, dipole-dipole IMF, dispersion forces IMF, bigger molecules generally have stronger dispersion forces.

HW: Nothing new. A chance to catch up as needed.

Monday, January 27, 2020

1.) "Like Dissolves Like" Solution Lab follow-up. Then hand it in.

2.) Workshop: Practice test and any questions relating to the test on Wednesday

HW: Finish/retry problems and explanations from the practice test. You'll hand in the practice test on Wednesday for a Habits of Learning grade. Test topics: VSEPR, polarity of bonds, polarity of molecules, IMFs and how they affect the properties of substances, hydrogen bonding IMF, dipole-dipole IMF, dispersion forces IMF, bigger molecules generally have stronger dispersion forces.

Friday, January 24, 2020

1.) "Like Dissolves Like" Solution Lab. Intro. to solutions and solubility.......and making use of our knowledge of IMFs.

2.) Workshop: Practice Test

HW: Finish up/retry problems from the practice test (VSEPR, polarity of bonds, polarity of molecules, IMFs and how they affect the properties of substances).

Wednesday, January 22, 2020

1.) Finish up the IMF Penny Lab.

*So, we tried determining the relative IMF strength of 5 liquids by seeing how much mass of each could be "piled" onto a penny before spilling over? Let's ponder our results.

*So, what OTHER physical properties of these liquids should correlate to IMF strength? Let's decide on one that we can look up the values for.

2.) Workshop: Practice Test (VSEPR, polarity, IMFs)

HW: Do the practice test (VSEPR, polarity of bonds, polarity of molecules, IMFs and how they affect the properties of substances)

Friday, January 17, 2020

1.) IMF Penny Lab: Determining our procedure. (Dependent, independent, control variables?)

2.) Carefully take and record your data. And how repeatable are your results? Let's try for at least 3 trials for each substance.

HW:

Wednesday, January 15, 2020

1.) IMF Penny Lab: Forming our hypotheses about the relative IMF strengths of water, hexane, methanol, ethanol, and butanol. You really need to know the 3 IMFs to do a reasonable job with this!

HW: Make your ranking of the IMFs clear, including your reasoning with reference to the IMFs. Like we discussed in class, if you could reason a couple different positions for a substance, say why.

Monday, January 13, 2020

I'm out with the plague.

1.) Option #1: IF you need finish up or catch up on any of our recent work, you may do so.

Option #2: Watch this geeky awesome video about the elements, but with the twist of actually seeing how we get them.

https://www.pbs.org/video/nova-hunting-the-elements/

HW: Catch up on anything from the course that you need to.

Wednesday, January 8, 2020

1.) A bit of sharing about jury duty, if you're interested.

2.) IMFs are forces BETWEEN molecules, not forces within a molecule.

3.) Review for Quiz on Friday. VSEPR, bond polarity, molecule polarity.

HW: Practice VSEPR and polarity problems. See the last assignment. Happy to help you with any of those we didn't go over together today. Also, there are plenty of other practice problems in the textbook right near where the last assignment's problems were.

Monday, January 6, 2020

1.) Quiz coming up on Friday this week. VSEPR (Vesper) theory as a way to determine the 3-D shapes of molecules. Polar and non-polar covalent bonds. Polar and non-polar molecules.

2.) Review of Intermolecular Forces.

*Hydrogen bonding, dipole-dipole, and dispersion forces

HW: Partial quiz review. #15, 34, 35, and 46 on pp. 216-218

Holiday Vacation

Friday, December 20, 2019

1.) Flame Test Lab

*Some minor practice naming chemical compounds.

*Another example of photons of specific energy/frequency/wavelength/color being emitted by atoms as electrons drop from higher stable electron energy levels to lower ones.

*Pretty colors!

HW: Play outside. Read a good book, eat cookies, and nap. Play outside some more.

Holiday Vacation

Wednesday, December 18, 2019

1.) Covalent bonds can be polar or non-polar (really just a matter of degree). How can we know?

2.) Determining if a MOLECULE is polar (not just if a BOND is polar)

3.) Intro to Intermolecular Forces (IMFs)

*Dipole-dipole forces *London dispersion forces *Hydrogen bonding (an IMF, not just a covalent bond involving hydrogen ! ! !)

HW: 1.) Read pp. 385-392 (This section is called "Intermolecular Forces", although the end of it mentions ionic compounds, which are not molecules....but they are weeny particles that stick together...)

2.) #1-12 on p.392. We will get to see a lot of these ideas playing out in the lab, too.

Monday, December 16, 2019

1.) Workshop: VSEPR homework problems.

2.) What is a polar bond? *Some covalent bonds are a fairly equal sharing of the electrons. *Some covalent bonds are NOT so equal in the sharing (but not outright ionic, though)! *How can we know when this happens?

3.) If a covalent bond can have a more positive and a more negative end, can a whole molecule have a positive and negative end? That is, can a MOLECULE be polar?

HW: 1.) Read pp. 194-198. (Electronegativity and Covalent Bonding).

2.) Questions #5, 6, and 11 on p.198.

Friday, December 13, 2019

1.) A VSEPR flowchart for you. Think of it as something Santa brought just for you. The last part of the flow chart is about whether a molecule is "polar" or not; we'll get to that very soon.

2.) Lab: Stabbing Clay Blobs #2 (AKA VSEPR Lab #2)

*So now you'll figure out the "molecular geometries", which is the shape of the resulting molecule when you consider the electron geometry and how many of the electron groups have atoms on the other end.

3.) OK, so let's give these "molecular geometries" their official names.

HW: 1.) #7 on p. 213. So, find the Lewis structure first (so you can see how many electron groups ("pairs"?!) are around the central atom), then the electron geometry, then the molecular geometry.

Wednesday, December 11, 2019

Early-release day. Classes a bit shorter.

1.) What does "VSEPR" actually stand for?! (And most folks pronounce is "vesper"). And Crosby whines and complains and suggests an improvement.

2.) Stabbing Clay Blobs Lab #1 (VSEPR Lab #1) follow-up.

Officially, you're learning about "electron geometries" in this lab. Naming the electron geometries. Electron geometries are just names for the ways the groups of electrons arrange themselves around a "central" atom.

3.) If time allows.......Lab: VSEPR #2 (this one is really about "molecular geometries")

HW: Nothing new.

Monday, December 9, 2019

1.) 3-dimensional shapes of molecules? Our Lewis structures are just flat representations of puffy 3-D thingies. So, how do we go about figuring out the 3-D shape? And does it matter?

2.) Lab: Stabbing Clay Blobs #1 (AKA VSEPR Lab #1)

HW: 1.) Read pp.208-213. (VSEPR theory....or...3-D shapes of molecules)

2.) Questions #1-3 on p.213.

Friday, December 6, 2019

1.) Test: Chemical bonding, naming chemical compounds.

HW: Nothing new. An opportunity to take care of any Chemistry stuff you have to take care of, though.

Wednesday, December 4, 2019

1.) Big ol' get ready for the test workshop.

HW: Test next class. Topics: chemical bonding (metallic, ionic, covalent), naming chemical compounds (names to formulas and formulas to names). You'll hand in the practice test next time, too.

Monday, December 2, 2019

1.) Heads Up! Test on Friday. Topics: Ionic, covalent, and metallic bonding; structural formulas (molecules and polyatomic ions); write chemical formulas knowing a compound's name; writing the name of a compound knowing it's formula.

2.) Metallic Bonding: So how the heck could this work?!

3.) Can our new (to us) model of metallic bonding explain some of the common properties of metals?

https://www.youtube.com/watch?v=Bjf9gMDP47s

4.) Alloy mini-research.

HW: 1.) Finish the alloys mini-research. (AKA Zombie Defense 101)

2.) Finish/refine/retry problems from the "namine" practice quiz.

Wednesday, November 27, 2019

1.) On-the-board-workshop: Making up 4 naming/formula problems. Then solving the ones someone else made up.

Formula to name. Or name to formula. You choose for each one.

a.) covalent (but not organic)

b.) ionic, but one that doesn't require a Roman number

c.) ionic, but one that DOES require a Roman number

d.) some fine organic compound (from the ones that you should know)

HW: OK, really finish the practice quiz.

Monday, November 25, 2019

1.) Workshop: Naming ionic compounds

2.) Workshop: Naming chemical compounds practice quiz

HW: Naming chemical compounds Practice Quiz

Friday, November 22, 2019

1.) Where do most of our alkanes come from? How do we separate them? How do we use them? Let's check out this video from Shell Oil company from the 1950s. It's a decent explanation of fractional distillation.

https://www.youtube.com/watch?v=hC1PKRmiEvs

2.) Naming ionic compounds. With emphasis on dealing with those Roman numbers. Why are they needed? (And you get a gift! A periodic table that includes the oxidation numbers! How awesome for you!)

3.) Workshop: Naming compounds.

HW: Make significant progress on the Naming Compounds and Writing Chemical Formulas practice quiz.

Wednesday, November 20, 2019

1.) Little Quiz: Alkanes and Alcohols

2.) Naming molecular (covalently bonded) compounds that AREN'T organic compounds.

3.) Naming ionic compounds.

HW: 1.) #10 on p. 207. #25 on p. 217. (Naming covalent compounds.)

2.) #19 -20 on p. 183-184. (Naming ionic compounds.)

Monday, November 18, 2019

1.) Alkane review and burning some stuff.

2.) The alcohols. What's the hydroxyl group? It's commonly occurring and is just an hydrogen bonded to an oxygen, which then can bond to, for example, a chain of carbons.

HW: Be ready for a very specific quiz next class. No the structures, formulas, and names of the alkanes and alcohols through decane and decanol. It's a nice pattern. Plus, know the "detailed" structural formula of how the OH group (hydroxyl) bonds and connects to a carbon chain.

Friday, November 15, 2019

1.) Organic Chemistry overview. https://www.youtube.com/watch?v=UloIw7dhnlQ

2.) The alkanes and the alcohols. Two of the simplest families of organic compounds.

3.) If we have time, we'll begin........Chemical nomenclature (how to name things).

Today we'll look at molecular compounds (covalently bonded compounds). Remember organic compounds (which are covalently bonded) have their own naming system.

HW: Know the alkanes up to decane! If it helps......"my elephant punches bunnies"

Wednesday, November 13, 2019

1.) Workshop: Polyatomic ion structural formulas (Lewis structures)

2.) Two "families" of organic compounds. From the covalent bonding simulation lab, did you notice now nicely carbon forms chains? This ability to form chains is called "catenation".

3.) Organic chemistry: a very broad overview.

HW: Read pp. 677-686. Intro. to carbon and organic compounds.

Friday, November 8, 2019

1.) Workshop: Covalent and ionic bonding problems. How did they go?

2.) Polyatomic ions. They form covalently, but end up making an ion that could be involved in ionic bonding! It's like cats and dogs living together. Sort of. Not really. Maybe.

3.) Your very own polyatomic ion sheet. Yay, coloring!

HW: Show the structural formulas (Lewis structures) for these polyatomic ions. Yes, use the polyatomic ion chart I gave you so that you know what the formula the overall charge is. CLEARLY show how electrons are either being added to the group from the "surroundings" or booted out....

a.) peroxide

b.) nitrite

c.) sulfate

d.) ammonium

e.) cyanide

Wednesday, November 6, 2019

1.) Efficiently (because we've definitely already done the "setup").........Lab: Burn, baby, burn (Covalent Bonding Lab)

2.) Workshop: Mixing up ionic bonding and covalent bonding situations.

HW: Think about how you showed the electron transfer (ionic bonding) or electron sharing (covalent bonding) during the bonding simulation labs. For the compounds shown down below,

a.) Determine what type of bonding you expect (ionic or covalent).

b.) For the ionic compounds, confirm that the chemical formula makes sense by clearly showing the electron transfer and the resulting ions.

c.) For the molecular compounds (covalent compounds), clearly show the structural formula (aka, Lewis structure) for the molecule (show bonding pairs with lines, show non-bonding electrons, too, like we did in the lab)

The fine and dandy compounds:

1.) K₂O (potassium oxide)

2.) N₂O (dinitrogen monoxide, laughing gas! ! ! which is an anesthetic. Big hint: The O is NOT in the middle.)

3.) CH₄ (methane)

4.) C₂H₄ (acetylene, as in.....an acetylene torch)

5.) C₈H₁₈ (octane)

6.) MgF₂ (magnesium flouride)

7.) SO₂ (sulfur dioxide, which contributes to smog and acid rain)

Monday, November 4, 2019

1.) OK, various folks missing Friday or today. Let's catch folks up on the Burn, Baby, Burn Lab, which is really about covalent bonding (and also an introduction to chemical reactions, specifically combustion reactions.)

HW: We got productively side-tracked about chemical reactions, combustion, and practical consequences of such. (Like heating your home, heat output, global warming, etc.) We'll catch up on the Burn, Baby, Burn Lab next time.

Monday, October 28, 2019

1.) Workshop: Periodic Trends Practice Test ....because there's a test on Wednesday.

HW: Refine and/or retry problems from the Periodic Trends Practice Test. You'll hand in the practice test for a Habits of Learning grade at the beginning of next class.

Test topics: Understanding what affects the electrical force between two objects; nuclear charge and effective nuclear charge; periodic trends in the force between a valence electron and the core of an atom; knowing what ionization energy, electronegativity, and atomic radius mean, and be able to explain their periodic trends; understand the affect that the extra stability of half-filled and filled sub-levels have on some of the properties (Hey, it's linked to why the exceptions to the diagonl rule happen!).

Friday, October 25, 2019

1.) We did the heavy lifting last class, figuring out how the force on the valence electrons due the positive "core" of the atom varies as we go across a period or down a group. (Effective nuclear charge! Distance between nucleus and valence electrons!) That makes what's next much easier.

2.) Ionization energy. What is it? Periodic trend? (And what's a mole?)

3.) Atomic radius. Hmmm...slightly tricky to define. Periodic trend.

4.) Electronegativity. What is it? Periodic trend?

HW: Make mighty progress on the Periodic Trends Practice Test

Wednesday, October 23, 2019

1.) Periodic Trends....continued.......The crucial idea for having them make physical sense? Understanding how the electrical force between the core of the atom and a valence electron is affected by the effective nuclear charge and the distance the valence electron is from the nucleus. So, using F=k*q1*q2/r^2 qualitatively.

2.) Ionization energy. What is it, and what trend do we expect?

3.) Ionization energy data look-up, spreadsheet, and scatter plot. How was our prediction? Anything funky showing up in the scatter plot? Hmm.....

4.) Trends for atomic radius (size) and electronegativity .

HW: 1.) Periodic Trends: Read pp. 132-141. Questions #1,2,5,6,8,10,11 on p.141.

Monday, October 21, 2019

1.) Quiz: Gravitational and electrostatic forces.

2.) If we have time today.............Nuclear charge vs. Effective nuclear charge. *AKA, what is "electron shielding"?

HW: Yet another catch up time. Quarter ends on Friday.

Friday, October 18, 2019

1.) Quiz on Monday on gravitational and electrostatic forces. Problems similar to the HW that is due today. Yes, I will provide the constants k and "Big G".

2.) Forces in atoms follow-up. *Can you find the gravitational force and electrostatic force? *Do you recognize how these forces compare for particles in an atom?!

3.) Introduction to periodic trends.

What do we mean by a "periodic trend"?

What's a period on the periodic table? What's a group (or family)?

Properties of elements we'll look at: atomic size, electronegativity, (first) ionization energy.

What are the periodic trends for these properties? And WHY?!?!?!

4.) If we have time today.............Nuclear charge vs. Effective nuclear charge. *AKA, what is "electron shielding"?

HW: 1.) Periodic Trends: Read pp. 132-137 (up to the "Electronegativity" sub-heading.

2.) Quiz on Monday. Quiz Prep: Practice gravitational and electrostatic force calculations, using your calculator effectively, paying attention to units.

Long Columbus Day Weekend, then PSATS for juniors on 10/16

Wednesday, October 9, 2019

1.) Forces in atoms ?

2.) Newton's Law of Gravitation follow-up and example problem.

3.) Coulomb's Laws of Electrostatics. Acts a lot like gravity, but it's the electrical CHARGE on the objects that matters, not the MASS.

4.) Workshop: Forces in atoms. And setting you up for the HW.

HW:

Assume an electron is 8x10^-9m away from the nucleus of a lithium-7 atom. Let's compare the electrostatic and gravitational forces between the electron and the nucleus.

a.) How many protons are in an atom of lithium-7?

b.) How many neutrons are in an atom of lithium-7?

c.) Assuming that protons and neutrons have a mass of about 1.67x10^-27kg each, what is the MASS of a lithium-7 nucleus?

d.) What is the mass of an electron? (Notes. Look it up. Whatever.)

e.) Clearly show your set-up (with units) and find the gravitational force between the electron and the nucleus.

f.) The charge on the electron is -1.6x10^-19C . The charge on each proton is +1.6x10^-19C . What is the total charge of the lithium-7 nucleus?

g.) Clearly show your set-up (with units) and find the electrostatic force between the electron and the nucleus.

h.) Which force is larger, the gravitational force or the electrostatic force? (See your answers for (e) and (g).

i.) How many times larger is the larger force?!?

Monday, October 7, 2019

1.) Questions from the ionic bonding HW?

2.) Forces in atoms.

How do the electrical forces between the electrons, protons, and neutrons in an atom compare to the gravitational forces?

*If we want to be able to think about and visualize why atoms do what they do, we might benefit from answering the above question.

*Newton's Law of Gravitation

*Coulomb's Law of Electrostatics

HW: Not ready for this yet !

Assume an electron is 8x10^-9m away from the nucleus of a lithium-7 atom. Let's compare the electrostatic and gravitational forces between the electron and the nucleus.

a.) How many protons are in an atom of lithium-7?

b.) How many neutrons are in an atom of lithium-7?

c.) Assuming that protons and neutrons have a mass of about 1.67x10^-27kg each, what is the MASS of a lithium-7 nucleus?

d.) What is the mass of an electron? (Notes. Look it up. Whatever.)

e.) Clearly show your set-up (with units) and find the gravitational force between the electron and the nucleus.

f.) The charge on the electron is -1.6x10^-19C . The charge on each proton is +1.6x10^-19C . What is the total charge of the lithium-7 nucleus?

g.) Clearly show your set-up (with units) and find the electrostatic force between the electron and the nucleus.

h.) Which force is larger, the gravitational force or the electrostatic force? (See your answers for (e) and (g).

i.) How many times larger is the larger force?!?

Friday, October 4, 2019

1.) Ionic bonding review and example problem.

2.) Here. Have a textbook.

3.) You can now predict the existence of lots of compounds ! We'll do several rounds of the following.

a.) Pick a metal and a non-metal.

b.) Determine the number of valence electrons each has. (Perhaps you'll do electron configurations to do this.)

c.) Show how electrons are transferred between however many atoms of your metal and non-metal are necessary until all become stable ions.

d.) Use what you did in (c) to predict the chemical formula for your ionic compound.

e.) Do a bit of online researching to see if your compound actually exists AND some interesting ways it is used.

4.) Workshop: Ionic bonding HW

HW: Read pp.166-175. (Ionic Bonding), then do these problems: Section Review #1-4,6-8 on p.175.

Wednesday, October 2, 2019

1.) Quiz check-in.

2.) Atoms react with other atoms, heading toward a stable situation.Stability, "8 is great, and 2 will do", and how metals and non-metals tend to behave in this regard.

3.) Ionic Bonding Simulation Lab

4.) Next time........ Yay! Your chemistry textbooks.

HW: Nothing new this time.

Monday, September 30, 2019

1.) Quiz: Topics: Electron configurations, electron dot diagrams, diagonal rule, periodic table and which sub-levels are filling, "8 is great, or 2 will do", filled outer levels?, orbital-filling diagrams, Hund's Rule.

2.) The Diagonal Rule is like warm sunshine on a crisp autumn day....but it does has it's flaws. Exceptions to the diagonal rule, and the underlying physical reason for these exceptions.

HW: If you need to re-take a test, here's a chance to prepare for it with no other chem homework gumming up the works.

Friday, September 27, 2019

1.) HW Check-in. Orbital-filling diagrams. (Hund's Rule !)

2.) Can the ORBTIAL-FILLING DIAGRAMS for iron and zinc predict anything about their BEHAVIOR ?!? Let's check and see.

3.) Which "zones" of the periodic table correspond to which sublevels receiving the "last" electron in an atom? This is a handy way to understand the periodic table.

4.) Workshop: What do you need some more help with before the quiz on Monday?

HW: 1.) Take care of business if you need to retry the first test. You should be aiming for the retake by early next week. Letting it linger just doesn't do you any good.

2.) Quiz on Monday. Topics: Electron configurations, electron dot diagrams, diagonal rule, periodic table and which sub-levels are filling, "8 is great, or 2 will do", filled outer levels?, orbital-filling diagrams, Hund's Rule.

Wednesday, September 25, 2019

1.) Heads Up! Quiz coming relatively soon. Probably Monday next week. Topics: Electron configurations, electron dot diagrams, diagonal rule, periodic table and which sub-levels are filling, filled outer levels?, orbital-filling diagrams, Hund's Rule.

2.) Element Mini-Research. Share what you found out.

3.) Nailing down..."8 is Great! (But 2 Will Do for H and He, and, well some of the other little atoms)" Oh yeah, and "stability" doesn't mean "neutral".

4.) Electrons act like little magnets. Spin. The spin quantum number (+1/2 or -1/2).

5.) Orbital-filling diagrams (or box-and-arrow diagrams) and Hund's Rule.

AKA "How to Sit on a Bus" . . . or . . . . "How to Sit at Cafe Tables in Paris Without Freaking People Out."

6.) If we have time today.......

Comparing the orbital filling diagrams for zinc and iron. Can we see any difference in how these materials behave ?!?

HW: 1.) Create orbital-filling diagrams ( box and arrow diagrams) for ....

a.) Nitrogen (N)

b.) Sulfur (S)

c.) Iron (Fe)

2.) Quiz coming soon. See topics listed up above. Probably want to practice some more orbital-filling diagrams. And can you reliably do the electron configurations, valence electrons, and electron dot diagrams?

Monday, September 23, 2019

1.) Electron configurations, valence electrons, electron dot diagrams (a.k.a. Lewis diagrams). You good?!

2.) Stability in systems sometimes is associated with certain numbers..... Cup Pyramid activity.

"8 is Great! (But 2 Will Do for H and He)"

3.) The staircase on the periodic table. What's it there for?

Metals, metalloids, and non-metals.

4.) Element Research.

HW: Pick one metal, one metalloid, and one non-metal. Hint: Pick ones that seem particularly interesting to you. Find out about each one. In particular, answer the following questions.

a.) What is its electron configuration and how many valence electrons does it have? Draw its electron dot diagram, too.

b.) Find out at least 2 or 3 uses for each material. In each use, is it used as a single element, or is it part of a compound or alloy?

c.) Where and how do we get this element? Is it inexpensive? Expensive? Rare or not? What kind of processing is necessary?

d.) What other interesting information or story can you share about this element?

Friday, September 20, 2019

1.) Diagonal Rule ! ! !

How can something so simple be so helpful in understanding the order the electron sub-levels fill in the quantum model of the atom?! I don't know, but I sure appreciate it.

2.) ELECTRON CONFIGURATIONS.......getting to know what's going on with the electrons in an atom is a LOT of what chemistry is about.

3.) Valence electrons and electron dot diagrams.

4.) The shape of the periodic table starts to reveal some mysteries.......

HW: Finish up the back of the "HW: Electron Configurations, Valence Electrons, Electron Dot Diagrams". It's the big table. Don't worry (yet) about the "Filled Outer Level?" column.

Wednesday, September 18, 2019

1.) Hand in your completed practice test. (Habits of Learning)

2.) Test: Early models of the atom and the discoveries/experiments/clever ideas that led us to change from one model to the next one. Details about isotopes and ions. Photon energy, wavelength, frequency calculations. E=hf and v=f*λ. Show your problem-solving clearly, including UNITS !

3.) If we have time......electron configurations (which are just a slick way of showing which electron sublevels the electrons in a mellowed-out (ground state) atom settle into). Turns out this is AMAZINGLY USEFUL for helping determine why the atoms behave like they do.

HW: Nothing new. So, it's a nice opportunity for you to work on what YOU need to work on.

Monday, September 16, 2019

1.) End results (for us) of the weirdness of electrons acting like waves in atoms? Energy levels, sub-levels, orbital shapes....

2.) Orbital shapes.

3.) *Energy levels and sublevels.

*"Smart People Don't Forget" and the diagonal rule

4.) Workshop: Practice Test questions?

HW: Models of the Atom Test on Wednesday ! Your practice test is due at the beginning of Wednesday's class.

Test Topics: Early models of the atom and the discoveries/experiments/clever ideas that led us to change from one model to the next one. Details about isotopes and ions. Photon energy, wavelength, frequency calculations. E=hf and v=f*λ. Show your problem-solving clearly, including UNITS !

Friday, September 13, 2019

1.) Intro. to the quantum mechanical model of the atom. The universe is WEIRD !

*Electrons behave like waves!?!! Wait, aren't they particles with mass? Yup, but objects, it turns out have wave-like characteristics, too. Including you. For large objects, the wave character is not really so apparent. For small objects (like electrons), the wave character is much more important to pay attention to in order to understand the behavior.

2.) Workshop: Practice Test (Models of the Atom through the Bohr Model)

HW: Finish up the Atomic Models practice test. Your whole goal is not to just "finish" it, but to re-try problems as necessary to build up your skills and confidence. SUPPORT YOUR WORK ! Remember, the test is on Wednesday. Practice Test will be collected before I hand out the tests.

Wednesday, September 11, 2019

1.) Heads up about the Atomic Models Test. Competency: Models of the Atom (Test date: Wednesday, September 18)

2.) Workshop: E=hf and v=f*λ relationships.

3.) Workshop: Practice Test

HW: Make major progress on the Practice Test (Atomic Theory: Through the Bohr Model). Please come visit me (yes, you can/should sign yourself up through advisory) with questions or just to work on it with convenient help nearby.

Test Topics: Early models of the atom and the discoveries/experiments/clever ideas that led us to change from one model to the next one. Details about isotopes and ions. Photon energy, wavelength, frequency calculations. E=hf and v=f*λ. Test date: Wednesday, September 18.

Monday, September 9, 2019

1.) "HW: Energy, Light, Line Spectra problems" Check-in. (we'll get back to (f) and (g) on each side in a little bit)

2.) What is light? (The quick version of the story).

3.) E_photon=hf

(This relates the energy of a photon, which is a "particle" of light, to its frequency.)

v=f*λ

(This relates the velocity of a traveling periodic wave to its wavelength and frequency.)

4.) Workshop: Practice using E_photon=hf and v=f*λ. UNITS ! ! ! Problems relating line spectra to electron energy levels to frequencies and wavelengths of the light that an atom emits.

HW: 1.) Finish #1-3 of the E_photon=hf and v=f*λ practice problems connected to the "What is Light? The fast version" handout. We started them in class.

2.) And now do (f) and (g) on each of the problems on the "Energy, Light, Line Spectra problems" handout.

Friday, September 6, 2019

1.) Quick HW check-in. How did it go?

2.) Line spectra (from excited atoms) and the connection the structure of atoms.

3.) Bohr Model of the atom (AKA the Planetary Model)

4.) Some background about light and some review about waves.

HW: 1.) Read the "What is Light?: The Fast Version" You don't need to try the problems on the second page yet.

2.) Finish the "HW: Energy, Light, Line Spectra problems" handout. Don't do parts (f) and (g) on either side, yet. We started this together in class.

Wednesday, September 4. 2019

1.) Elements, ions, and isotopes.

We'll use the PHET "Build an Atom" simulation to help remind us about these.

https://phet.colorado.edu/sims/html/build-an-atom/latest/build-an-atom_en.html

2.) Continue our story about the models of the atom.......... How did we get from the Rutherford Model (AKA the Nuclear Model) to the Bohr Model (AKA the Planetary Model)? And what are "line spectra" and what do they have to do with the model of the atom?!

HW: Do the "HW: Drawing atoms, isotopes, and ions" handout. Hopefully what we did in class should help out.

Long Labor Day Weekend

With the puppy atoms, you considered the cycling of material in the universe.

Fully practice this concept by going to a fair this weekend, eating too much fried dough, then going on a ride and ralphing it up again. Look! Materials cycling! (Hint: This is seriously optional.)

Wednesday, August 28, 2019

1.) Puppy Atoms check-in.

a.) Get together with a partner and share your ideas about the puppy atoms.

b.) Maybe using both your ideas, modify and improve your answers, then get ready to share this with the class.

c.) Come back together as a class and share and argue about what you think are the best answers. Be kind as you argue productively.

d.) Repeat a,b, and c for the energy from the fire.

2.) Demo: Discovery of the electron. And what new model of the atom did this lead to?

3.) So, we are all happy with our new model of the atom. . . . then Rutherford's Gold Foil Experiment happened. So, now what?!

Video reviews of Rutherford's Gold Foil Experiment.

.... Brian Cox's version with a lame use of tennis balls. http://www.youtube.com/watch?v=wzALbzTdnc8

.....Bruce Kennedy's modern set-up (and he looks like a friend of mine from college). http://www.youtube.com/watch?v=XBqHkraf8iE

4.) Atom, ion, isotope review.

So why is one atom an atom of carbon and one silicon or uranium? Also, what's an ion? What's an isotope?

PHET's "Build an Atom" simulation (link below ) may help remind you about atoms, ions, and isotopes.

https://phet.colorado.edu/sims/html/build-an-atom/latest/build-an-atom_en.html

Click on "Atom"

Show the Net Charge and the Mass Number by hitting the plus signs.

Check the box that says Stable/Unstable

HW: Use the PHET "Build an Atom" link (See #4 above.) until you definitely know what parts of an atom go where (in the nucleus or not), know how nitrogen atoms are different than lithium atoms, know what an isotope is, and know what an ion is. Then answer the questions on the "Drawing atoms, isotopes, and ions" handout. You will want access to a periodic table. I gave you a paper copy in class. You can also get one online. (www.ptable.com is a good one)