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Name: _______________________________________
Block: ________
Date: ______________
Chemistry Midterm Practice
Note: This set of problems does NOT cover all of the concepts that will be on the midterm. Remember to
study your class notes and handouts for a full review!
1. Which sequence represents a correct order of historical developments leading to the modern model
of the atom?
A. The atom is a hard sphere  most of the atom is empty space with a small dense nucleus 
electrons exist in orbitals outside the nucleus
B. The atom is a hard sphere  electrons exist in orbitals outside the nucleus  most of the atom is
empty space with a small dense nucleus.
C. Most of the atom is empty space with a small, dense nucleus  electrons exist in orbitals outside
the nucleus  the atom is a hard sphere.
D. Most of the atom is empty space with a small dense nucleus  the atom is a hard sphere 
electrons exist in orbitals outside the nucleus.
2. According to the modern model of the atom, which of the following best shows the behavior of
electrons?
A. Orbiting the nucleus in fixed paths.
B. Found in regions outside the nucleus called orbitals.
C. Combined with neutrons in the nucleus.
D. Located in a solid sphere covering the nucleus.
3. Which symbols represent atoms that are isotopes?
A. C-14 and N-14
B. O-16 and O-18
C. I-131 and I-131
D. Rn-222 and Ra-222
4. Compared to a proton, an electron has
A. A greater amount of charge and the same sign
B. A greater amount of charge and the opposite sign
C. The same amount of charge and the same sign
D. The same amount of charge and the opposite sign
5. Which pair of particles is found in the nucleus?
A. Proton and electron
B. Proton and neutron
C. Neutron and electron
D. Neutron and beta particle
6. An ion with 8 protons, 8 neutrons, and 10 electrons is represented by
A. Ne
B. O+2
C. O-2
D. O
7. What is the chemical formula for a compound formed from calcium ions (Ca2-) and chloride ions(Cl–)?
a. CaCl
b. Ca2Cl
c. CaCl2
d. Ca2Cl2
8. What is the mass number of an atom which contains 28 protons, 28 electrons, and 34 neutrons?
A. 28
B. 56
C. 62
D. 90
9. According to the Chemistry Reference Tables, what substance has a melting point of -94oC and a
boiling point of 65oC?
a. Ethanol
b. Chlorine
c. Hexane
d. Methanol
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10. The diagram below shows the results of Rutherford’s experiment in which he used a radioactive
source to “shoot” alpha particles at a thin sheet of gold foil.
Based on these results, what were Rutherford’s conclusions?
A. Atoms are solid matter with positive and negative charges scattered throughout.
B. Atoms are solid, positively charged matter with negatively charged electrons scattered
throughout.
C. Atoms are mostly empty space with small, dense, positively charged centers.
D. Atoms are mostly empty space with small, dense, negatively charged centers.
Use the chart below to answer the question below.
11. The chart shows isotopes of some common elements. In what two properties of carbon do the
isotopes of carbon differ?
a. Atomic number and number of neutrons
b. Atomic mass and number of neutrons
c. Mass number and number of protons
d. Number of protons and number of neutrons
12. Ionic compounds tend to form between which pair of elements?
a. metals and metals
c. nonmetals and nonmetals
b. metals and nonmetals
d. metalloids and noble gases
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13. Given the diagrams X, Y, and Z below. Which diagram or diagrams represent a mixture of elements
A and B?
A. X only
B. X and Y
C. Z only
D. X and Z
14. A physical change occurs when
A. a peach spoils
B. a bracelet turns your wrist green
C. a copper bowl tarnishes
D. a glue gun melts a glue stick
Use the chart below to answer the following questions
15. What type of bonding is mostly likely in compound A?
A. IONIC
B.COVALENT
C. METALLIC
D. NONE
16. What type of bonding is most likely in compound C?
A. IONIC
B.COVALENT
C. METALLIC
D. NONE
17. What type of bonding is most likely in compound D?
A. IONIC
B.COVALENT
C. METALLIC
D. NONE
18. Which of the following substances best illustrates polar covalent bonding?
a. HCl
b. NaBr
c. CsF
d. Cl2
19. The methane, CH4, gas molecule exhibits what type of geometric shape?
a. trigonal planar
b. tetrahedral
c. bent or V-shaped
20. Which bond is the most polar?
a. HCl
b. HBr
c) HI
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d. HF
d. trigonal pyramidal
21. The diagram represents the arrangement of atoms in a metallic solid. Scientists believe that electrons
in the outer energy levels of the bonding metallic atoms are free to move from one atom to the next.
Because they are free to move, these electrons are often referred to delocalized electrons and give
metals ALL of the following properties EXCEPT.
A. Conduct heat and electricity in the solid state.
B. Brittle, break easily
C. Malleable and ductile.
D. Luster
22. Which of the following molecules is trigonal planar in shape?
a. BH3
b. O3
c) NH3
d) CH4
23. Which diagram best represents the structure of a water molecule?
24. If two elements have similar chemical properties, which of the following would be similar in both
elements?
a. atomic radii
c. number of outer electrons
b. number of energy levels
d. atomic mass
Use the chart below to answer the following questions:
25. Which element is most likely to gain electrons?
a. A
b. B
c. C
d. D
e. E
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26. What is the electron configuration of element C?
a. 1s2, 2s2, 2p6
b. 1s2, 2s2, 2p1
c. 1s2, 2s2, 3s1
d. 2s2, 2p3
27. What element is a metalloid?
a. A
b. B
c. C
d. D
e. E
28. Which atom has an octet?
a) A
b) B
c) C
d) D
e) E
d) D
e) E
29. Which atom will form a +2 ion?
b) A
b) B
c) C
30. Which of the following is the correct noble gas configuration for iron?
a. [Ar] 3d64s2
b. [Ne] 3d64s2
c. [Xe] 3d64s6
d. [Ca] 4s2
31. 5.00 moles of sodium have a mass of
a. 4.60 g
b. 23.0 g
c. 115 g
d. 55.0 g
32. Which compound has the smallest molar mass?
a. a. CO
c. H2O
b. b. CO2
d. H2O2
33. What is the orbital notation for a chlorine atom in the ground state?
34. How many molecules of hydrogen chloride gas (HCl) are in 73.0 g of the gas.
a. 6.02 x 1023 molecules
c
9.03 x 1023 molecules
b. 36.5 molecules
d
1.2 x1024 molecules
35. Which conversion factor would you use to calculate correctly the mass of 2 moles of the element
titanium?
a.
c.
b.
d.
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36. Which type of electromagnetic energy has the shortest wave length?
a.
Visible light
b.
Radio waves
c.
Ultraviolet radiation
d.
Gamma radiation
37. The mathematical equation c= λν means that as the wavelength (λ) increases, the frequency (ν)
decreases. The equation E = hν means that as frequency increases, energy increases. Using this
information and the reference tables, which color of visible light has the least energy?
A. Red
b. Yellow
c. Green
d. Violet
38. If an electron drops from n=6 to n=2, what type of electromagnetic radiation is emitted?
A. Ultraviolet (UV)
b. Visible
c. Infrared (IR)
d. Radiowaves
39. How many protons and electrons are in a 6429Cu2+ ion?
A) 27 protons, 29 electrons
C) 27 protons, 31 electrons
B) 29 protons, 27 electrons
D) 29 protons, 31 electrons
40. How does an S2− ion differ from an electrically neutral sulfur atom?
A. mass number
C) atomic number
B. nuclear charge
D) number of electrons
41. When 4219K undergoes radioactive decay, the result is two products, one of which is calcium-42.
What is the other product?
A. 42He
B. 24He
C. 11e
D. 0−1e
42. Which orbital notation represents a p-block element in the 3rd period?
43. Which is correct for the following regions of the electromagnetic spectrum?
UV
IR
A.
high energy
short wavelength
low energy
low frequency
B.
high energy
low frequency
low energy
long wavelength
C.
high frequency
short wavelength
high energy
long wavelength
D.
high frequency
long wavelength
low frequency
low energy
44. After writing out its orbital notation (boxes and arrows), what is the total number of unpaired electrons
in an atom of germanium (atomic number 32)?
A.
0
B.
1
C.
6
2
D.
3