Download Unit 1 Test

Pre-IB Chemistry I
Unit 1 Test, Ms. Kiely
1. Which of the following is a solution?
a. salt water
b. beef stew
c. sand and water
d. oil and vinegar
2. Separating a solid from a liquid by evaporating the liquid is called ____.
a. filtration
b. condensation
c. boiling
d. distillation
3. Which of the following is a mixture?
a. baking soda
b. mayonnaise
c. sucrose
d. table salt
4. Which of the following is true about compounds?
a. They can be physically separated into their component elements.
b. They have compositions that vary.
c. They are substances.
d. They have properties similar to those of their component elements.
5. A substance that can be separated into two or more substances only by a chemical change is
a(n):
a. solution
b. element
c. mixture
d. compound
6. Which of the following materials is a substance?
a. air
b. gasoline
c. stainless steel
d. silver
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7. Which state of matter is characterized by having an indefinite shape, but a definite volume?
a. gas
b. liquid only
c. solid only
d. both b and c
8. Which of the following is true for all chemical reactions?
a. The total mass of the reactants increases.
b. The total mass of the products is greater than the total mass of the reactants.
c. The total mass of the products is less than the total mass of the reactants.
d. The total mass of the reactants equals the total mass of the products.
9. A certain sample of element Z contains 60% of 69-Z and 40% of 71-Z. What is the relative
atomic mass of element Z in this sample?
A. 69.2
B. 69.8
C. 70.0
D. 70.2
10. Which of the following sets of symbols represents isotopes of the same element?
a.
b.
c.
d.
J
J
J
L
L
L
M
M
M
Q
Q
Q
11. Information is given about four different atoms:
atom
neutrons
protons
W
22
18
X
18
20
Y
22
16
Z
20
18
Which two atoms are isotopes?
A. W and Y
B. W and Z
C. X and Z
D. X and Y
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12. Which statement is correct about the isotopes of an element?
A. They have the same mass number
B. They have the same atomic number
C. They have more protons than neutrons
D. They have the same numbers of protons and neutrons
13. What is the difference between two neutral atoms represented by the symbols
210
85
210
84
Po and
At?
A. The number of neutrons only.
B. The number of protons and electrons only.
C. The number of protons and neutrons only.
D. The number of protons, neutrons and electrons.
14. Which idea of John Dalton’s proposals is no longer considered part of the modern view of
atoms?
A. Atoms are extremely small.
B. Atoms of the same element have identical masses.
C. Atoms combine in simple whole number ratios to form compounds
D. Atoms of different elements can combine in different ratios to form different compounds.
15. The smallest particle of an element that retains the properties of that element is a(n) ____.
a. atom
b. electron
c. proton
d. Neutron
16. Which of the following is true about subatomic particles?
a. Electrons are negatively charged and are the heaviest subatomic particle.
b. Protons are positively charged and the lightest subatomic particle.
c. Neutrons have no charge and are the lightest subatomic particle.
d. The mass of a neutron nearly equals the mass of a proton.
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17. What is the difference between two neutral atoms represented by the symbols
59
28
27
Co and
Ni?
A. The number of neutrons only.
B. The number of protons and electrons only.
C. The number of protons and neutrons only.
D. The number of protons, neutrons and electrons.
18. List the number of protons, neutrons, and electrons in
C.
19. Consider an element Z that has two naturally occurring isotopes with the following percent
abundances: the isotope with a mass number of 19.0 is 55.0% abundant; the isotope with a mass
number of 21.0 is 45.0% abundant. What is the average atomic mass for element Z?
20. A fictitious element X is composed of 10.0 percent of the isotope
, 20.0 percent of the
isotope
, and 70.0 percent of the isotope
. Estimate the atomic mass of element X.
21. The element chromium, Cr, has four naturally occurring isotopes. Use the relative abundance of
each to calculate the average atomic mass of chromium.
Cr = 4.34%,
Cr = 83.79%,
22. The element vanadium has two isotopes,
Cr = 9.50%,
50
23
V
and
Cr = 2.37%.
51
23V,
and a relative atomic mass of 50.94.
(a) Define the term isotope.
(1)
(b) State the number of protons, electrons and neutrons in
50
23V.
(2)
(c) State and explain which is the more abundant isotope.
(1)
(d) Define the term relative atomic mass.
(1)
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