Download Unit 2 Test Review - Liberty High School

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Unit 2 Test Review
Matter and Atomic Structure
Complete the following problems to help prepare you for you Unit 2 Test. You more than likely will want
to answer these questions on a separate piece of paper (unless you can write microscopically). In addition
to these problems, review your notes, assignments (#29-44), labs, and chapter 3 & 4 in your textbook. 
1. Classify each as an element (E), a compound (C), or a mixture (M).
a. Brass
b. Tungsten
c. Sodium chloride
d. Air
2. Classify each of the following as a physical (P) or chemical (C) change.
a. Evaporating alcohol
b. Sanding a table top
c. Grinding grain
d. Fermenting fruit juice
3. Which of these is a chemical property?
a. Ice melts at 0° C
b. Oxygen is a gas
c. Helium is very nonreactive
d. Sodium is a soft, shiny metal
e. Water has a high specific heat capacity
4. Draw and explain on the molecular level the different phases of matter.
5. If sodium melts at 97.72° C and boils at 882.8°C, what is its physical state at 80°C? At 250°C?
6. What is a pure substance made up of more than one kind of atom called?
7. Describe the difference between a compound and an element. Give two examples of each.
8. How can a solution be distinguished from a compound?
9. Define and give an example of each:
a. Homogenous mixture
b. Heterogeneous mixture
c. Suspension
d. Solution
10. Nitrogen oxide (NO) and nitrogen dioxide (NO2) are both made up of nitrogen and oxygen. Can
you assume that they will both have similar physical and chemical properties? Why or why not?
11. An 18-L sample of element A (density 0.84 g/mL combines completely with a 4-L sample of
element B (density 2.34 g/mL) to form the compound AB. What is the mass of the compound
formed?
12. A substance breaks down into three component elements when it is heated. The mass of each
component element is listed in the table below. What was the mass of the substance before it was
heated?
Component
Mass (g)
A
39.10
B
54.94
C
64.00
13. Silver iodine powder has been used as an antiseptic and as an agent to seed clouds for rain. Silver
iodine is 45.9% silver by mass. If you separate a 50.0-g sample of silver iodine into its elements,
silver and iodine, how much silver would you have?
14. If 5 g of element A combines with 16 g of element B to form compound AB, how many grams of
B are needed to form AB2? How many grams of B are needed to form AB3?
15. During a chemical reaction, 2.445 g of carbon reacts with 3.257 g of oxygen to form carbon
monoxide gas. How many grams of carbon monoxide are formed in this reaction?
16. Ibuprofen has the chemical formula C13H18O2. It is 75.69% carbon, 8.80% hydrogen, and 15.51%
oxygen. How many mg of carbon does a .2-g tablet of ibuprofen contain?
17. During a chemical reaction, 4.032 g of hydrogen combined with oxygen to form 36.032 g of
water. How many grams of oxygen reacted?
18. Carbon and oxygen combine to form carbon monoxide (CO) and carbon dioxide (CO2). The
masses of oxygen that combine with 12 g of carbon to form these two compounds are 16 g and 32
g, respectively. What is the ratio of the masses of oxygen in CO2/CO.
19. Phosphorus and chlorine combine to form two different compounds. In one compound, 3.88 g of
phosphorus combines with 13.28 g of chlorine. In the other compound, 1.32 g of phosphorus
combines with 7.56 g of chlorine. Do these data support the law of multiple proportions? Show
your work.
20. Ferric chloride is 34.4% iron and 65.6% chlorine by mass. A chemist analyzes three compounds
that contain iron and chlorine. Her results are summarized in the data table below. Which of these
compounds is likely to be ferric chloride? Explain your answer.
Mass of the Sample
Compound
Mass of Fe (g)
Mass of Cl (g)
(g)
I
25.0
9.30
15.7
II
25.0
8.60
16.4
III
27.0
9.30
17.7
21. The chemical formula for baking soda is NaHCO3. A 168.02-g sample of baking soda contains
45.98 g of sodium, 2.02 g of hydrogen, 24.02 g of carbon, and 96.00 g of oxygen. What is the
mass percentage of each element in baking soda?
22. The chemical formula for chalk is CaCO3. A 100-g sample of chalk contains 40 g of calcium, 12 g
of carbon, and 48 g of oxygen. What is the mass percentage of each element in chalk? What
would be the mass of calcium in 200 g of chalk?
23. A 17.0-g sample of ammonia, NH3, contains 3.0 g of hydrogen. What percentage of ammonia is
hydrogen? How many grams of nitrogen does the sample contain?
24. Discuss the different models proposed by Dalton, Thomson, and Rutherford. Include a drawing of
each of their models.
25. Describe Rutherford’s gold foil experiment and why he was able to determine that an atom has a
positive nucleus where all the atom’s mass is and the rest is mostly empty space with electrons
moving around it in.
26. Complete the table for the following elements.
# of
# of
# of
Atomic
Element
Atomic #
Protons
Electrons
Neutrons
Mass
25
30
Manganese (Mn)
11
12
Sodium (Na)
35
45
Bromine (Br)
39
89
Yttrium (Y)
27. What is an isotope?
28. Give the number of protons, electrons, and neutrons in each of the following atoms.
a. 108 Ag
b.
c.
47
40
Ca
20
23
Na
11
29. How many neutrons does europium-151 have? What is the isotope’s mass number?
30. Neon has two isotopes: neon-10 and neon-12.
a. Which isotope has the greater mass?
b. Which has more neutrons?
c. Which has more protons?
d. Which has more electrons?
31. Use the table below to calculate the atomic mass of element X. then use the periodic table to
identify the element. Show all your work.
Isotope
Mass (amu)
Percent Abundance
16
X
15.995
99.762
17
X
16.999
0.038
18
X
17.999
0.200
32. Magnesium has three isotopes. Magnesium-24 has a percent abundance of 78.99%. Magnesium26 has a percent abundance of 11.01%. What is the percent abundance of magnesium-25?
Assume that there are no other magnesium isotopes.
33. A sample of hydrogen is 99% 1H, 0.8% 2H, and 0.2% 3H. What is its average atomic mass?
34. Calculate the atomic mass of iridium. Iridium has two isotopes. Iridium-191 has a mass of 191.0
amu and a percent abundance of 37.58%. Iridium-193 has a mass of 193.o amu and a percent
abundance of 62.42%. Show all your work.
35. An element has three naturally occurring isotopes. Information about each isotops is summarized
below.
Isotope
Mass (amu)
Percent Abundance
Isotope 1
23.985
78.70
Isotope 2
24.946
10.13
Isotope 3
25.983
11.17
a. Write each isotope in symbolic notation.
b. Find the atomic mass of this element. Show all your work.
c. Identify the element, using the periodic table.
36. Fill in the data table below.
Nuclear Particle
Mass
Charge
Symbol(s)
Alpha
β or 0 e
−1
0
0
37. Americium-241 ( 241Am) undergoes alpha decay (inside a smoke detector)
38. Iodine-131 (131I) undergoes normal beta decay (used in therapy for hyperthyroidism)
39. Fluorine-18 (18F) undergoes positron emission (one of the radionuclides used in PET scans)
40. Technetium-99m (99mTc) undergoes gamma decay to form 99Tc (a diagnostic radioactive tracer
used to locate tumors, the “m” indicates a metastable excited nuclear state)