FUNDAMENTALS
UNIT TWO REVIEW:
Introduction to Matter, Properties of Matter and Basic Atomic Structure
PROPERTIES OF MATTER
1. Which of the following are chemical changes and which are physical changes?
a. melting iron physical
e. burning hydrogen chemical
b. a cut healing chemical
f. digesting a Big Mac chemical
c. receiving a tattoo chemical
g. tearing paper physical
d. exploding dynamite chemical
h. evaporating salt water physical
2. Identify each of the following as being elements, compounds, homogeneous mixtures
(solutions) or heterogeneous mixtures (for juice-assume it DOES NOTE have pulp).
a. Iron (Fe) element
h. ocean water homogeneous mixture
b. dirt heterogeneous mixture
i. sugar (C6H12O6) compound
c. rubbing alcohol compound
j. pineapple juice homogeneous mix.
d. salt water homogeneous mixture
k. corn syrup homogeneous mixture
e. Italian salad dressing heterogeneous mix. l. lemonade homogeneous mixture
f. milk homogeneous mixture
m. granite heterogeneous mixture
g. mercury (Hg) element
n. water (H2O) compound
3. Identify each of the following as either chemical properties or physical properties. If they are
physical properties identify them as either intensive or extensive.
a. burning in air chemical
f. volume physical – extensive
b. boiling point physical - intensive
g. density physical - intensive
c. malleability physical - intensive
h. shape physical - intensive
d. color physical - intensive
i. odor physical - intensive
e. melting point physical - intensive
j. stability chemical
4. Explain the difference between a homogeneous mixture (solution) and a heterogeneous
mixture.
♦ Homogeneous mixtures are uniform and composed of one phase while heterogeneous
mixtures have more than one identifiable phase.
5. What are the evidences for a chemical change (seven indicators of a chemical reaction)?
♦ New odor, gas forming/bubbles, color change, change in temperature, explosion, light
is produced, precipitate formed
6. Know the difference between the three states of matter in terms of shape, volumes,
compressibility, and particle spacing.
Solid
Liquid
Gas
Description
-Definite shape
-Takes shape of
-Fills container
-Definite volume
container
-Changeable volume
-No compressibility
-Constant volume
-Easily compressed
-Very little motion
-No compressibility
-Particles move freely
-Particles slide past
each other
7. Know the four different methods for separating mixtures mentioned in the book: filtration,
distillation, crystallization and chromatography.
♦ Filtration: a separation technique that uses a porous barrier to separate a solid from a
liquid (example is sand and water mixture through filter paper and funnel)
♦ Crystallization: a separation technique that results from the formation of pure solid
particles of a substance from a solution contained a dissolved substance (example is
rock candy forming from sugar water)
♦
♦
Chromotography: a technique that separates components from a mixture, the mobile
phase, as they travel across the surface of another material, stationary phase (example
is black ink separates into different components as it spreads across filter paper)
Distillation: a separation technique that is based on the differences in boiling points of
the substances involved (example is distilling water to remove impurities)
Review Questions from the Video: NOVA Kaboom!
8. What are the ingredients in gun powder?
♦ Saltpeter (KNO3), charcoal, and sulfur (S)
9. What gives nitroglycerin so much energy?
♦ The “nitro group” which can store a lot of energy and is highly explosive in air
10. What are the characteristics common to plastic explosives?
♦ You can mold them into any shape, you can handle them aggressively, they have a
high blasting potential, and need a detonator to activate them
11. What was the hope of scientists who detonated the atomic bomb and the father of high
explosives regarding their explosives?
♦ Tried to create the perfect weapon, an end all to war.
12. Conservation of mass problems:
a. From a process that splits water to form hydrogen and oxygen, a scientist collected
20.0 grams of hydrogen and 159 grams of oxygen. How much water was originally
involved in the process?
Water  hydrogen + oxygen
x grams = 20.0 grams + 159 grams
x grams = 179 grams
b. In a flask, 20.3 grams of aluminum reacted with bromine to form 263.0 grams of
aluminum bromide. How many grams of bromine reacted?
Aluminum +
bromine

aluminum bromide
20.3 grams
+ x grams =
263.0 grams
-20.3
-20.3
Bromine(reacted) = 242.7 grams
13. Percent by mass problems:
a. A 156 gram sample of an unknown compound contains 25 grams of hydrogen.
What is the percent by mass of hydrogen in the compound?
𝑚𝑎𝑠𝑠 𝑜𝑓 𝑒𝑙𝑒𝑚𝑒𝑛𝑡
25 𝑔𝑟𝑎𝑚𝑠
% by mass =
× 100 =
× 100 = 16%
𝑚𝑎𝑠𝑠 𝑜𝑓 𝑐𝑜𝑚𝑝𝑜𝑢𝑛𝑑
156 𝑔𝑟𝑎𝑚𝑠
b. If 7.0 grams of substance X reacts with 21 grams of substance Y to form the
compound XY, what is the percent by mass of each element in the compound?
X + Y
= XY
7.0 g + 21 g = 28 g
𝑚𝑎𝑠𝑠 𝑜𝑓 𝑒𝑙𝑒𝑚𝑒𝑛𝑡
7.0 𝑔𝑟𝑎𝑚𝑠
% by mass X = 𝑚𝑎𝑠𝑠 𝑜𝑓 𝑐𝑜𝑚𝑝𝑜𝑢𝑛𝑑 × 100 = 28 𝑔𝑟𝑎𝑚𝑠 × 100 = 25%
𝑚𝑎𝑠𝑠 𝑜𝑓 𝑒𝑙𝑒𝑚𝑒𝑛𝑡
% by mass Y = 𝑚𝑎𝑠𝑠 𝑜𝑓 𝑐𝑜𝑚𝑝𝑜𝑢𝑛𝑑 × 100 =
21 𝑔𝑟𝑎𝑚𝑠
28 𝑔𝑟𝑎𝑚𝑠
× 100 = 75% OR (100% - 25% = 75%)
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c. Two unknown compounds are tested. Compound 1 contains 90.0 grams of
hydrogen and 180 grams of oxygen. Compound 2 contains 45 grams of hydrogen
and 90.0 grams of oxygen. Are the compounds the same?
Compound 1: 90.0 grams + 180 grams = 270 grams
90.0 𝑔𝑟𝑎𝑚𝑠
× 100 = 33% hydrogen
100% - 33% = 67% oxygen
270 𝑔𝑟𝑎𝑚𝑠
Compound 2: 45 grams + 90.0 grams = 135 grams
45 𝑔𝑟𝑎𝑚𝑠
× 100 = 33% hydrogen
100% - 33% = 67% oxygen
135 𝑔𝑟𝑎𝑚𝑠
YES, THE COMPOUNDS ARE THE SAME
d. If 5.11 g of hydrogen reacts completely with 46.5 g of oxygen to form hydrogen
peroxide, what is the percent by mass of hydrogen in hydrogen peroxide?
Hydrogen + Oxygen  Hydrogen peroxide
𝑚𝑎𝑠𝑠 𝑜𝑓 𝑒𝑙𝑒𝑚𝑒𝑛𝑡
% by mass = 𝑚𝑎𝑠𝑠 𝑜𝑓 𝑐𝑜𝑚𝑝𝑜𝑢𝑛𝑑 × 100 =
5.11 𝑔𝑟𝑎𝑚𝑠
46.5 𝑔𝑟𝑎𝑚𝑠
× 100 = 11%
STRUCTURE OF ATOM
1. Know what the difference in masses of isotopes of the same element is due to.
DIFFERENT NUMBERS OF NEUTRONS
2. Know the charges and masses of protons, electrons, and neutrons
PARTICLE
CHARGE
MASSES
+
PROTON
POSITIVE (p )
1 amu
0
NEUTRON
NEUTRAL (n )
1 amu
ELECTRON
NEGATIVE (e-)
1/1840 amu
3. Know how to calculate the number of protons, neutrons and electrons in an atom
when given its isotope mass and atomic number.
As an example: Lead (Pb) has an atomic number of 82. An isotope of lead has a mass
of 206 amu. Calculate the number of protons, neutrons and electrons in an atom of
this isotope. How would you write the isotope symbol for this isotope of lead?
NUMBER OF PROTONS = ATOMIC NUMBER = NUMBER OF ELECTRONS = 82
NUMBER OF NEUTRONS = MASS NUMBER – NUMBER OF PROTONS
NUMBER OF NEUTRONS = 206 - 82 = 124
ISOTOPE SYMBOL= 𝟐𝟎𝟔
𝟖𝟐𝑷𝒃
4. When given the isotope symbol for an element be able to give its number of protons,
electrons and neutrons.
As an example: Give the number of each of these particles for 70
30𝑍𝑛.
NUMBER OF PROTONS = NUMBER OF ELECTRONS = 30
NUMBER OF NEUTRONS = 70-30 = 40
5. Know the contributions of the following individuals according to the models we talked about
in class.
A.
B.
C.
D.
E.
Bohr: ELECTRONS ORBIT THE NUCLEUS AND ARE CERTAIN ORBITS OR ENERGY LEVELS
J.J. Thomson: PLUM PUDDING MODEL; DISCOVERED THE ELECTRON
Millikan: DID AN OIL DROP EXPERIMENT TO DETERMINE THE CHARGE ON AN ELECTRON
Rutherford: GOLD FOIL EXPERIMENTS, NUCLEUS IS POSITIVELY CHARGED
Dalton: CHEMICAL ATOMIC THEORY, ATOM IS INDIVISIBLE
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6. What is the name for the current model of the atom that we use today? Briefly describe this
model.
QUANTUM MECHANICAL MODEL: ELECTRONS ARE IN CLOUDS, ELECTRONS CAN BEHAVE LIKE
WAVE OR PARTICLE
7. Be able to draw a Bohr model for elements 1-10. For the element BORON, determine the
following:
# electrons __5____
# protons __5___ # neutrons ___6____
# energy levels___2____
# valence electrons ___3________
Electrons in the outer ring are called valence
electrons. In this picture there are 3 dots (electrons) in
the outer ring, so Boron would have 3 valence
electrons
8. What is the name for the location where electrons are found? ENERGY LEVELS OR ORBITALS
9. What are valence electrons? ELECTRONS IN OUTERMOST ORBITAL
10. What are ions? What is the name for atoms that gain electrons? Lose electrons?
IONS ARE ATOMS THAT HAVE GAINED OR LOST MORE THAN ONE ELECTRON
CATIONS LOSE ELECTRONS AND ARE POSITIVE
ANIONIS GAIN ELECTRONS AND ARE NEGATIVE
11. Oxygen gains two electrons, write the symbol for the ion. O-2
12. Lithium loses one electron, write the symbol for the ion. Li+1
REVIEW FROM CHAPTERS 1 AND 2 TEST:
1. What is the volume of an object with a density of 5.70 g/mL and a mass of 15.28 g?
𝑴
𝟏𝟓.𝟐𝟖 𝒈
𝑽 = 𝑫 = 𝟓.𝟕𝟎 𝒈/𝒎𝒍 = 2.68 mL
2. What is the volume of an object whose density is 0.75 g/mL and who mass is 15.28 g?
𝑴
𝟏𝟓.𝟐𝟖 𝒈
𝑽= =
= 20 mL
𝑫
𝟎.𝟕𝟓 𝒈/𝒎𝒍
3. What is the mass of an object whose density is 10.02 g/mL and whose volume is 35 mL?
𝒈
𝑴 = 𝑽 × 𝑫 = 𝟑𝟓 𝒎𝑳 × 𝟏𝟎. 𝟎𝟐 𝒎𝑳 = 350 grams
4. Metric Conversions:
a. 23mg
= ___0.023________ g
b. 1.92 Km = ___19200________ dm
c. 455 mL = ___.0455_________ daL
d. .085 g = ___8.5___________ cg
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