1. Words to Study for Chem. Test
Mass
Weight
Matter
Physical Properties
Chemical Properties
Characteristic Properties
Physical Changes
Chemical Changes
Signs of Chem. Change
States of Matter
Atoms
Solid
Liquid
Gas/Gas Laws
Change of State
Melting/Melting Point
Boiling/Boiling Point
Freezing/Freezing Point
Evaporation
Condensation
Sublimation
Endo/Exothermic

2. Words to Study for Chem. Test
Solution
Solubility
Suspensions
Colloids
Pure Substance
Element
Compound
Mixture
Homogeneous Mixture
Heterogeneous Mixture
Chemical Formulas
Chemical Equations
Reactants
Products
Subscripts
Coefficients
Law of Conservation of Mass
Decomposition Reaction
Replacement Reaction
Synthesis Reaction

3. Chemical Formulas
A combination of chemical symbols and numbers to represent a substance
Examples
H20: Water
CO2: Carbon Dioxide
NaCl: Salt
C6H1206: Sugar

4. Chemical Equations
A representation of a chemical reaction that uses symbols to show the relationship between the reactants and the products
Examples
C O2  CO2
2H2 + O2  2H2O

5. Reactants
A substance or molecule that participates in a chemical reaction
Examples
C O2  CO2
Reactants
2H2 + O2  2H2O

6. Products A substance that forms in a chemical reaction Examples
C O2  CO2
Product
Zn + 2HCl  ZnCl2 + H2

7. Subscripts
A number written below and to the right of a chemical symbol in a formula
Tells how many atoms of that element are present
Examples
CO2
H20
C6H12O6

8. Coefficients
A number that is placed in front of a chemical symbol or formula
Tells how many molecules of that substance are present
Keeps reaction balanced
Example
2H2 + O2  2H2O

9. Law of Conservation of Mass
Mass is neither created nor destroyed in ordinary chemical and physical changes
Must start and end with the same amount
Example
Log Fire  Ashes Smoke
30 kg kg kg kg

10. Decomposition Reaction
A reaction in which a single compound breaks down to form two or more simpler substances
Example
H2CO3  H2O + CO2

11. Replacement Reaction
A reaction in which one element takes the place of another element in a compound
Example
Zn + 2HCl  ZnCl H2

12. Synthesis Reaction
A reaction in which two or more substances combine to form a new compound
Example
2Na + Cl2  2NaCl

13. Solution
A homogeneous mixture of 2 or more substances evenly dispersed throughout a single phase
Looks like one thing
Usually when 1 substance is dissolved in another, but not always
Examples: Lemonade, Air, Bronze, Gatorade

14. Solubility Ability of 1 substance to dissolve in another
To dissolve more quickly: Crush it, Stir it, Heat it
Solute – the substance that is dissolved
Solvent – what substance is being dissolved in
Example: Sugar dissolves in water

15. Suspensions
A mixture in which particles of a material are more or less evenly dispersed throughout a liquid or gas
When you shake it, it looks like one thing, but if you leave it setting, particles will settle to bottom
Example: Snow Globe

16. Colloids
Mixture consisting of tiny particles that are intermediate in size between those in solutions and those in suspensions
Particles aren’t so small that they completely dissolve like solutions, but aren’t so big they settle
These particles can scatter light
Example: Milk, Mayo, Deodorant

17. Homogeneous Mixture Looks like or appears to be only 1 substance
Example
Gatorade
Lemonade

18. Heterogeneous Mixture
Looks like or appears to be more than 1 substance

19. Pure Substance
Sample of matter, either a single element or a single compound, that has a definite chemical & physical properties
Made of only 1 type of particle
Elements or Compounds
Elements – made of atoms
Compounds – made of molecules

20. Element
A substance that can’t be separated or broken down into simpler substances by chemical means
Pure substance
Can’t be broken down at all
Made of one type of atom
Found listed on Periodic Table

21. Compound
Substance made up of atoms of 2 or more different elements chemically combined with specific mass ratio
Can only be separated by chemical changes
Made only of molecules
H20: Water
NaCl: Salt
C6H12O6: Sugar
Fe2O3: Rust
Properties of compound are completely different from the properties of elements that formed it

22. Mixture
Combination of 2 or more substances that are not chemically combined
2 or more things physically in the same place
Examples: Salad, Cereal, Pizza, Omelette

23. Change of State
Change of a substance from one physical form to another
Requires adding or removing energy so that particles can speed up or slow down

24. Endothermic
Energy is absorbed by a substance or substances

25. Exothermic
Energy is released from a substance or substances

26. Melting Change of state when a solid becomes a liquid
Particles must speed up
Add energy/heat
Endothermic

27. Melting Point Temperature at which a substance melts
Water: 32°F or 0°C

28. Freezing Change of state from a liquid to a solid
Particles must slow down
Remove energy/heat
Exothermic

29. Freezing Point Temperature at which a substance freezes
Water: 32°F or 0°C

30. Evaporation
Change of a substance from a liquid to a gas (only on surface)
Particles (on surface) must speed up
Add energy/heat
Endothermic

31. Boiling Change of a liquid to a gas (throughout an entire liquid)
Particles (on bottom of liquid) must speed up
Add energy/heat
Endothermic
**Won’t happen unless air pressure equals pressure in bubbles

32. Boiling Point Temperature at which a substance boils
Water: 212°F or 100°C
At Sea Level: boiling depends on air pressure

33. Condensation Change of state from a gas to a liquid
Particles must slow down
Remove energy/heat
Exothermic

34. Sublimation Change of state from a solid to a gas Skips liquid stage
Example: Dry Ice
Skips liquid stage
Add energy/heat
Endothermic

35. To Access the BBC Video:
In Internet Explorer, go to
Click on Unit 2
Under Class Files/Links, click on Behavior of Matter Test Bite (BBC)
When finished, turn in questions to your period’s colored drawer 

36. Atoms
Smallest unit of an element that maintains the properties of that element
Can not be broken down into anything smaller
Scientists used to think they couldn’t be split, but we now know that was incorrect

37. States of Matter
The physical forms of matter, which include solid, liquid, and gas

38. Solid
The state of matter in which the volume and shape of a substance are fixed
Definite shape
Definite volume
Particles are tightly packed
Particles barely move
They vibrate in place

39. Liquid
The state of matter that has a definite volume but not a definite shape
No definite shape
Definite volume
Particles move fast enough to separate a little
Allowing them to change shape
Particles do not move fast enough to change volume

40. Liquid (Continued) Viscosity: a liquid’s resistance to flow
High Viscosity: Slow Flow (Honey)
Low Viscosity: Fast Flow (Water)
Surface Tension: force that attracts the molecules at the surface of a liquid to form the drop

41. Gas The state of matter that does not have a definite shape or volume
No definite shape
No definite volume
Particles move so fast that they completely separate from each other
Allowing them to change shape and volume

42. Gas Laws If Temperature remains Constant, Hallway
Volume Increases, Pressure Decreases
Volume Decreases, Pressure Increases
Inversely Proportional
If Pressure remains Constant,  Balloon
Temperature Increases, Volume Increases
Temperature Decreases, Volume Decreases
Directly Proportional

43. Physical Changes
A change of matter from one form to another without a change in chemical properties
Usually reversible, no change to matter composition
End with the same thing you started with
Examples:
Ripping
Crushing
Cutting
Heating
Cooling
Coloring
All changes of state

44. Chemical Changes
A change that occurs when one or more substances change into entirely new substances with different properties
Never reversible
End with something different than you started with
Examples:
Soured Milk
Burning
Digesting
Cooking/Baking
Rotting/Spoiling
Tarnishing

45. Signs of a Chemical Change
Change in color
Change in temperature
Fizzing/Foaming
Sound or light being given off
New smell
New taste
Precipitate – when two liquids are mixed together and form a solid

46. Mass A measure of the amount of matter in an object
Mass of an object is the same no matter where it is located
Only way to change is to add or take away matter
Unit/Tool:
Grams (g)
Balance

47. Weight A measure of the gravitational force exerted on an object
Changes when the force of gravity changes
Differs on Earth & Mars
Unit/Tool:
Newtons (N)
Spring Scale

48. Matter Anything that has mass and takes up space
Made up of tiny particles called atoms
Atoms: smallest particle of matter

49. Physical Properties
Can be observed or measured without changing the matter’s identity
Adjective – descriptive word
Examples
Color
Smell
Size/Shape
Texture/Taste
Temperature
Density
State (Solid, Liquid, Gas)

50. Chemical Properties
Substance ability to participate in chemical reactions
Hard to observe
In order to see these you must change the substance into a new substance
Examples
Flammability
Reactivity

51. Characteristic Properties
Chemical or physical property that is always the same no matter what size the sample is
Can be physical or chemical
Most useful type of property
Examples
Density
Flammability
Reactivity
Boiling Point, Melting Point, Freezing Point
Color
Smell