Chemistry Course Competencies

The main Chemistry Competencies:

Models of the Atom (including the quantum model)

Chemical Bonding and Nomenclature

Periodic Trends

3-D Shapes of Molecules and Inter-particle Forces

Chemical Reactions and Stoichiometry

Solutions, Solubility, and Concentration

Behavior of Gases

Acids and Bases

Specific Competencies are below.

Developing Models of the Atom (mostly review) – Specific Competencies

1. Can explain that our current understanding of atoms is a great example of how scientific ideas develop. Our model of the atom has changed over time as more observations have been made, causing the development of new models.
2. Can describe the progression of atomic models: “indestructible ball”, plum-pudding model, Rutherford’s model(nuclear model), and Bohr’s model (planetrary model). (Quantum model will be addressed in the next unit.)
3. Through diagrams and written description, can describe the key experiments/observations that led to each new model being developed (cathode rays, Rutherford’s gold foil experiment, line spectra)
4. Demonstrates an understanding of the connection between number of protons, number of neutrons, number of electrons, and type of atom, which isotope, and ion charge.
5. Can draw specific isotopes of atoms with the correct number and placement of electrons, neutrons, and protons.
6. Can draw ions with the correct number and placement of electrons, neutrons, and protons.
7. Draw and explain how Rutherford’s gold foil experiment shows that the nucleus exists, all the positive charge of the atom is concentrated in the very small nucleus, and that the atom is mostly empty space occupied by electrons.
8. Explain the connection between line spectra, stable electron energy levels, and how come the electrons in an atom don’t just crash right into the positive nucleus. Can perform calculations involving the energy of a photon, it's frequency, and it's wavelength.
9. Understands that all materials (cars, hamsters, plants, stars...) are made up of the approximately 100 types of atoms shown on the periodic table. Some materials only contain one type of atom. Others are made up of many types.

Quantum Model of the Atom – Specific Competencies

1. Understands that the common perception of electrons orbiting around the nucleus of an atom (sort of the Bohr model) like planets orbiting the sun is NOT our current model of the atom.
2. Understands, at a basic level, that particles have wave-like qualities (particularly relevant to small particles like electrons) that make it difficult (Or futile? Or meaningless?) to pinpoint their actual locations exactly at a given moment in time.
3. Can explain that the quantum model predicts that electrons don't occupy orbits, but rather occupy orbitals, which are specifically shaped regions in space around the nucleus that are associated with a certain amount of energy.
4. Can draw s and p orbitals (and is familiar with d and f orbitals, but won't be asked to draw these).
5. Can use the diagonal rule to identify the order in which electron energy levels and their sub-levels are filled by electrons (from lowest to higher energy orbitals). Recognizes that the diagonal rule is surprisingly accurate for such a simple tool, but there are a few exceptions (This course expects students to recognize the Cr/Mo, and Cu/Ag/Au exceptions.)
6. Knows that that individual orbitals can hold up to 2 electrons.
7. Knows that s sub-levels have 1 orbital, so can contain 2 electrons; p sub-levels have 3 orbitals, so can contain 6 electrons; d sub-levels have 5 orbitals, so can contain 10 electrons; f sub-levels have 7 orbitals, so can contain 14 electrons.
8. Recognizes that the shape of the periodic table is directly related to which electron sub-levels are being occupied by that particular element. Can label a periodic table to show the 1s, 2s, 3s.....2p, 3p, 4p.....3d, 4d.....4f, 5f... blocks.
9. Can write electron configurations for the elements.
10. Can explain that valence electrons are the electrons that occupy the highest energy level in a given element when in the ground state.
11. Understands that chemical reactions, for the most part, involve the sharing, stealing, and losing of these valence electrons among atoms.
12. Can use the electron configuration to identify the number of valence electrons.
13. Can write electron dot diagrams (Lewis diagrams) for atoms.

Chemical Bonding and Nomenclature – Specific Competencies

1. Knows that atoms of different elements can bond to form new substances that often have very different properties from the original elements.
   1. Can identify elements either metals, non-metals, or metalloids, and knows where they are on the periodic table. (For example, non-metals are to the right of the “staircase”.)
   2. Can identify the properties of metals, non-metals, and metalloids.
   3. Can identify that it is the electrical forces among parts of the atoms that is the major reason that atoms bond the way they do.
   4. Understands that the number of valence electrons an atom has is highly related to it's stability, and that chemical bonding is generally the shifting or sharing of valence electrons among the atoms to achieve more stable arrangements. (“8 is great! But 2 will do for H and He.”)
   5. Understands that non-metals tend to share valence electrons with each other when forming compounds, and that this is known as covalent bonding.
   6. Understands that a metal and a non-metal will typically form a compound with the metal giving up electrons and the non-metal taking electrons, and that this is knows as ionic bonding.
   7. Understands that metal atoms can hold onto each other by a process called metallic bonding, which involves the valence electrons forming a “sea of electrons” among a matrix of positive atomic cores.
   8. Understands that for covalent bonding, a single pair of electrons may be shared (single bond), two pairs of electrons may be shared (double bond), or three pairs of electrons may shared (triple bond).
   9. Given a covalent compound or polyatomic ion, can draw electron dot diagrams, figure out how the atoms could successfully bond, and draw the corresponding Lewis structure.
   10. Given a metal and a non-metal, can draw electron dot diagrams, clearly show how electrons are transferred, and can successfully predict the chemical formula for the ionic compound that could be formed.
   11. Can successfully give the correct chemical formula of a covalent or ionic compound when given the name of the compound.
   12. Can successfully give the name of a covalent or ionic compound when given the formula of the compound.
   13. Knows what an organic compound is and that they are often named differently than other covalent compounds.
   14. Can successfully name or give the chemical formula for the alkanes and the alcohols.

Periodic Trends - Specific Competencies

1. Understands that the shape of the periodic table and the location of the elements on it are related both to the electron arrangements of the atoms and the properties of the elements, and that this is no coincidence.
2. Can explain the difference between nuclear charge and effective nuclear charge (which requires understanding what electron shielding is).
3. Can explain what is meant by atomic size, electronegativity, and ionization energy.
4. Knows the periodic trends for atomic size, electronegativity, and ionization energy.
5. Can explain these trends in terms of electrostatic force, effective nuclear charge, and the distance between the nucleus and the valence electrons.
6. Can explain that the extra stability of filled and half-filled sub-levels causes ionization energies to be slightly higher for those elements. (And realizes this is also the underlying reason for the exception to the diagonal rule addressed earlier.)

3-D Shape of Molecules and Inter-particle Forces (or Intermolecular Forces) - Specific Competencies

1. Knows that the 3-D shape of the little arrangements of particles (ions, metal atoms, or molecules) has a large effect upon the property of the substance.
2. Can explain the relationships between the inter-particle forces of a substance and the substance's presence as a solid, liquid, or gas (at room temperature, for example), and what is generally true about the substance's melting and boiling points.
3. Knows that many interactions in biology (neurotransmitters, drugs, protein synthesis) are greatly determined by the 3-D shapes of molecules and ions.
4. Extends his or her knowledge from the previous units and now can connect electronegativity differences between atoms to the type of bond that they will form.
5. Can explain the difference between non-polar and polar covalent bonds (and link this to electronegativity differences).
6. Can use VSEPR theory to predict the 3-D shapes of (fairly simple) molecules. This involves a chain of understandings and skills: valence electrons, Lewis diagrams, covalent bonding, determining electron geometries, and determining the final molecular geometry. Course will emphasize competence with molecules having no more than four electron groups around the central atom.
7. Can use VSEPR and his or her knowledge of polar bonds to determine if a molecule is, overall, a permanent dipole.
8. For molecules, understands how these neutral objects can end up being attracted to each other in the following ways: 1.) dispersion forces (non-polar/non-polar), 2.) dipole forces (polar/polar), and 3.) hydrogen bonding.
9. Can explain that a non-polar molecule can be a temporary dipole (people at a dance analogy)
10. Can make predictions about certain bulk properties of substances (like boiling point or surface tension) based upon an understanding of IMFs and how the strength is influenced by molecule size (dispersion), degree of polarity, or the presence of hydrogen bonding.

Chemical Reactions, Collision Theory, and Stoichiometry - Specific Competencies

1. Understands that chemical reactions involve one or more substances (reactants) interacting to become a new substance or substances (products).
2. Can differentiate between a chemical change and a physical change.
3. Understands that chemical reactions involve the rearrangement of how atoms are connected and how their electrons are distributed, but DO NOT involve changes in the nuclei of the atoms (which would be nuclear reactions).
4. Knows that chemical reactions usually involve taking in energy from the surroundings (endothermic, it feels cold) or releasing energy to the surroundings (exothermic, it feels hot). (This course typically does not require quantitative calculations of energy changes in reactions, though it is an easy extension for students who are interested.)
5. Understands the basics of Collision Theory: In order for a reaction to occur, the reactants must 1.) collide, 2.) collide with sufficient energy to react, and 3.) collide at the correct orientation. Can connect this understanding to reaction rates and how rates are influenced by the phase of the reactants, concentration, and temperature.
6. In this course, students will need to be able to identify and be familiar with the following types of reactions: combustion, synthesis, decomposition, single-displacement, double-displacement, and redox reactions (including total ionic reactions, net ionic reactions, and half-reactions).
7. Given a word description of a reaction (including names, but not formulas) for some of the substances involved, can write the corresponding chemical reaction. (Example: Propane burns on your stove at home. Write the chemical reaction.)
8. Can give a basic explanation of how combustion reactions are used extensively by humans, including for transportation, heating buildings, producing electricity, etc.
9. Can give a basic explanation of how combustion reactions are related to, as examples, climate change, smog, acid rain, and carbon monoxide poisoning.
10. Can make use of solubility charts and activity series to predict if specific single-displacement and double-displacement reactions will actually occur or not, and, if they do, what the products will be.
11. Understands why the mole is such a useful idea.
12. Understands the difference between an individual atom's atomic mass and the average atomic mass of a large collection of atoms of a particular element.
13. Can find the molar mass of elements and compounds.
14. Consistently demonstrates the usefulness and efficiency of using conversion factors when solving problems.
15. Can reliably convert between mass, # of moles, and # of particles for a given sample of a substance.
16. Can balance chemical equations, and understands that it makes sense to do so from a conservation of mass or conservation of atoms point of view.
17. Can perform the basic types of stoichiometric calculations for a reaction: mole-mole, mole-mass, mass-mole, mass-mass, etc. Does so reliably and clearly using conversion factors.

Solutions, Solubility, and Concentration - Specific Competencies

1. Understands that many chemical reactions occur in solution since the reactants are quite mobile and have a chance to interact.
2. Understands the meanings of solvent and solute.
3. Understands that a solution DOES NOT need to be a liquid. Gasses and solids can be solutions, too. (Alloys, for example.)
4. Is familiar with “Molar” (M) as a common unit for concentration for liquid solutions. (I M = 1 mole/Liter)
5. Can solve quantitative problems involving concentration, volume, and grams or number of moles.
6. Can make specific quantities of specific concentrations of solutions in the lab.
7. Given a stock solution of known concentration, can perform the necessary calculations and make a specific volume of a less concentrated solution.
8. Can connect the “Like dissolves like” rule of thumb for solubility to how non-polar and polar molecules (or ions, which are “extremely polar”) interact in solution.
9. Can successfully predict what solvents can dissolve what solutes. (Basic examples.)

Gas Laws - Specific Competencies

1. Can explain that the force on the inside surface of a closed container is caused by gas particles colliding with it. And pressure is the force per unit of area.
2. Is familiar with multiple units of pressure: PSI, Pascals, kilopascals, atmospheres, mmHg. And given access to conversion information, can convert from one to the other.
3. Can explain that the pressure exerted by a gas depends upon the amount of gas in the container, the temperature of the gas, and the volume of the container.
4. Can write the ideal gas law equation by picturing HOW the pressure of a gas should change as the other factors change (see #3). P = nRT/V where R is a constant.
5. Understands that Fahrenheit, Celsius, and Kelvin are all common temperature scales, and that the Kelvin scale needs to be used for gas law calculations.
6. Can solve quantitative problems using the ideal Gas Law.
7. Can make use of the “Gas Laws With Funny Names” relationships, but recognizes that it is easy to predict these relationships by picturing molecules doinking around inside a container. Also, recognizes that the ideal gas law actually includes these more limited relationships.
8. Knows what STP (Standard temperature and pressure) is.
9. Can calculate and make use of the fact that 1 mole of any (ideal) gas at STP has a volume of 22.4 Liters.
10. Can make use of #9 in stoichiometry problems. (For example: How may liters of carbon dioxide are produced when your car uses 1 gallon of gas? (Assume the carbon dioxide is at STP).

Acids and Bases - Specific Competencies

1. Understands that acid-base reactions are another useful way of understanding some types of chemical reactions.
2. Can identify some common acids and bases, and can identify typical properties and potential dangers.
3. Understands the Arrhenius definition of an acid and a base. Can identify such substances as acids or bases.
4. Understands that there are other, more broadly applicable, definitions of acids and bases (Bronsted-Lowry definition, and Lewis definition). This course will introduce these ideas, but will concentrate on the Arrhenius definition.
5. Can explain what a chemical equilibrium is. Specifically, can differentiate between a static and dynamic equilibrium. Understands what is meant by the forward reaction and the reverse reaction. Understands that some reactions are “completion reactions” and others are not, and how they are different.
6. Can explain that the strong hydrogen-bonding in a liquid water sample can cause a small amount of auto-ionization, leading to one H⁺ to “jump ship” from one water molecule to another.
7. Understands that H⁺ is really going to be H₃0⁺ in solution. In acid-base calculations, you will see both used.
8. Knows that, in pure water, the concentrations of H⁺ and OH^- are equal and are both 1x10^-7 M.
9. Knows that pH is related to the concentration of H⁺ in the solution, and specifically that pH = -log[H⁺]
10. Can perform concentration and pH calculations.
11. Knows the difference between a weak acid or base and a strong acid or base, and clearly understands that this is different than concentration.
12. Can clearly explain how, for example, a solution of a weak acid could have a lower pH (more acidic) than a solution of a strong acid.
13. Understands that the pH scale runs from 1-14, with 7 being neutral. 1 is most acidic. 14 is most basic.