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Chem1 Unit 2: Matter and Energy (14 days)

Essential Questions

How can we describe matter?
How are matter, energy, and temperature related?

Vocabulary

·      physical change – a change that occurs when an object changes shape or appearance but NOT chemical structure

·      chemical change – a change in which an object changes chemical structure to form a new substance

·      indicators of chemical change – evidence that shows a chemical change has taken place; they are: release/absorption of heat/light, color change, formation of a gas, formation of a precipitate

·      nuclear change – a change in which the nucleus of an object changes to form a new element or elements

·      fission – a nuclear reaction in which a nucleus is split into several smaller nuclei

·      fusion – a nuclear reaction in which smaller nuclei are fused together to form one larger nucleus

·      physical property – a property of matter that can be measured through direct observation (i.e. you can measure the property without changing the identity of the substance)

·      malleable – the ability of an object to be smoothly pounded into a sheet

·      brittle – materials that break or shatter easily

·      chemical property – a property that can only be observed by changing the substance into a different substance

·      microscopic – to a chemist, on the scale of atoms

·      macroscopic – on the scale that can be directly seen and measured

·      element – a type of matter that contains only one type of atom

·      compound – a type of matter that contains two or more different elements that are chemically bonded together

·      homogeneous mixture – a mixture containing two or more compounds/elements that is uniform (the same) throughout

·      heterogeneous mixture – a mixture containing two or more compounds/elements that is NOT uniform (the same) throughout

·      atom – the smallest unit of an element (e.g. P, Ar, He, etc.)

·      molecule of an element – a group of atoms of the same element chemically bonded together (e.g. H2, O2, N2, etc.)

·      molecule of a compound – a group of atoms of different elements chemically bonded together (e.g. H2O, CO2, NaCl, NaOH, HCl, etc.)

·      chemical formula – a combination of element symbols and subscripts that tell you the ratio of elements in a compound

·      solution – homogeneous mixture made up of a solvent and solute(s)

·      solute – any substance that is dissolved into a solution

·      solvent – substance that makes up most of the solution; it is usually a liquid

·      concentration – the amount of solute compared to the total solution

·      dilute – a solute that contains relatively little solute compared to solvent

·      concentrated – a solution that contains a lot of solute compared to solvent

·      unsaturated – a solution that holds less than the maximum amount of solute possible at a given temperature

·      saturated – a solution that holds exactly the maximum amount of solute possible at a given temperature

·      supersaturated – a solution that holds more than the maximum amount of solute possible at a given temperature; this kind of solution is very unstable

·      rate of solutions formation – speed at which things dissolve (i.e. how quickly a solute dissolves in a solvent)

·      agitation – stirring

·      kinetic-molecular theory – a theory that explains the observed thermal and physical properties in terms of the average behavior of a collection and molecules; for gases, it states that gas molecules are 1) very far apart and 2) in constant, random motion

·      (NOT for mastery) compressible – the ability of an object to be squeezed (compressed)

·      temperature (T) – the average kinetic energy of particles in an object due to their random motions through space

·      pressure – a measure of how much randomly moving particles hit the surface of a container

·      sublimation – a phase change that occurs when solids turn into gases

·      deposition – a phase change that occurs when gases turn into solids

·      Fahrenheit (oF) – a temperature scale with 180 degrees between the freezing point of water (32oF) and the boiling point of water (212oF)

·      Celsius (oC) – a temperature scale with 100 degrees between the freezing point of water (0oC) and the boiling point of water (100oC)

·      Kelvin (K) – a temperature scale that starts at absolute zero and has the same size degrees as Celsius degrees

·      heat – thermal energy, energy due to temperature; it flows between objects

·      1st Law of Thermodynamics – the total initial energy of a system in EQUAL TO the total final energy of the same system (i.e. energy cannot be created nor destroyed, only transferred)

·      2nd Law of Thermodynamics – heat energy flows from higher temperature to lower temperature

·      specific heat (c) – the amount of energy required to raise one gram of a substance by one degree Celsius

·      delta (Δ) – a symbol used in science to mean “change in”


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  Jun 21, 2012, 11:41 AM Emilie Siverling
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