Unit 7 Study Guide:
Atoms, Elements/Compounds/Mixtures, States of Matter, Physical and
Chemical Properties and Changes
1. Famous scientists in the study of the atom: Name, dates, and
contribution. See summary on page 203.
Date
Contribution
Aristotle
425BC
Earth, Air, Fire, Water, Aether
Democritus
425BC
Matter is made of indivisible
atoms
John Dalton
1802
Atomic Theory of Matter
Joseph Priestly 1772
Discovered Oxygen
Antoine Lavoisier
1783
1st Chemistry Textbook,
L.O.C.M.
J.J. Thomson
1897
Discovered the electron
Ernest Rutherford
1909
Discovered the proton
Niels Bohr
1913
Proposed electron energy levels
Gilbert Lewis
1916
Proposed the term ‘valence’
James Chadwick 1932
Discovered the neutron
2. Using the Periodic Table to find the characteristics of an atom:
Consider Phosphorous P-15. See practice pages 211, 213, 218.
Atomic Symbol:
Atomic Number:
Atomic Mass:
Protons:
Electrons:
Neutrons:
Group:
Period:
Electron Shells:
Valence Electrons:
Ionic State:
Type:
Most common Isotope:
P
15
30.97
15
15
16
Bohr Model
Lewis Model
5
2
3
5
-3
non metal
P-31
3. Classifying matter; mixture or pure substance, homogeneous or
heterogeneous, and compound or element.
Substance mixture/pure substance
homo/hetero/compound/element
 Sand
M
 Fruit punch
M
 Magnesium
P
 Baking Soda (NaHCO3)
P
Hetero
Homo
E
C
4. Properties of matter physical or chemical


Physical properties are the senses and measurements and can be
observed without changing the substance.
Chemical properties are reactivity, or flammability. They cannot
be observed except in a chemical reaction.
Characteristic
 Smell
 Bubbles
 Color change
 Length
Physical
X
Chemical
X
X
X
Observation
Physical Change
 Alka Seltzer in water
 A melting popsicle
X
 Dissolving Kool-Aid in water
X
 Frying French-fries
Chemical Change
X
X
5. Knowing the relationship between the following terms:
Atom is to Element: an atom is the smallest part of an element that
retains the characteristics of that element
Molecule is to Compound
: a molecule is the smallest part of a
compound that retains the characteristics of that compound
6. An intensive property versus an extensive property
Intensive: a property of a substance that does not change with the
size of the sample
Extensive: a property of an object that changes with the size of the
sample




Characteristic
Length
Density
Melting Point
Mass
Intensive or Extensive
Ex
In
In
Ex
7. Law of Conservation of Mass
The mass of the reactants must equal the mass of the products
8. Kinetic Molecular Theory
All matter is in motion; the more heat energy added, the more
kinetic energy of the particles
9. Using the L.O.C.M. to determine the mass of reactants or products
10. 18g of water are formed from 2 grams of hydrogen and 16g of
Oxygen
11. 58g of NaCl are formed from 23g Na and 35g Cl.
12. Separating Mixtures. How would you separate a mixture of sand,
salt, and iron filings?
Magnet for iron, dissolve salt in water, filter sand out, evaporate
water to recover salt
13. Identifying state of matter, compounds, or mixtures looking at
representative molecule models.
B
A






Salt in water
A solid
A Liquid
A Gas
A compound
A mixture
C
B
A
C
D
E
F
D
E
F
14.Kinetic Molecular Theory and the phases of matter. P.244
 When energy is added, molecules speed up, and spread out.
 Temperature is the measurement of the relative kinetic energy of
matter.
 A solid remains at the same temperature as it melts or freezes
because of its heat of fusion.
 A liquid remains at the same temperature as it boils or condenses
because of its heat of vaporization.
15. Be able to calculate density to the correct number of decimals
(limited to the fewest in the math), when D=M÷V
16.Solutions: The lesser part of the mixture is the solute (what gets
dissolved), the greater part of the mixture is the solvent (what
does the dissolving).