Chemistry
Section
_____
Name:
_____________________________
MID TERM STUDY GUIDE Date:
_________________________
A. Multiple Choice.
1. The mass of a proton is approximately equal to the mass of
(1) an alpha particle (2) a beta particle
(3) a positron
(4) a neutron
2. An orbital of an atom is defined as the most probable location of
(1) an electron
(2) a neutron
(3) a positron
(4) a proton
3. At STP, which physical property of aluminum always remains the same from sample to sample?
(1) mass
(2) density
(3) length
(4) volume
4. What must occur when an electron in an atom returns from a higher energy state to a lower
energy state?
(1) A specific amount of energy is released.
(3) The atom undergoes transmutation.
(2) A random amount of energy is released.
(4) The atom spontaneously decays.
5. Which phrase describes the distribution of charge and polarity of a CH4 molecule?
(1) symmetrical and polar
(3) asymmetrical and polar
(2) symmetrical and nonpolar
(4) asymmetrical and nonpolar
6. Which list of elements consists of a metal, a metalloid, and a nonmetal?
(1) Li, Na, Rb
(2) Cr, Mo, W
(3) Sn, Si, C
(4) O, S, Te
7. Which diagram represents a mixture of two different molecular forms of the same element?
8. Which substance can be decomposed by a chemical change?
(1) beryllium
(2) boron
(3) methanol
(4) magnesium
Created 17 January 2017
9. Which Lewis electron-dot diagram represents a nitrogen atom in the ground state?
10. What is the most likely electronegativity value for a metallic element?
(1) 1.3
(2) 2.7
(3) 3.4
(4) 4.0
11. Which polyatomic ion has a charge of 3–?
(1) chromate ion
(2) oxalate ion
(4) thiocyanate ion
(3) phosphate ion
12. Which equation represents natural transmutation?
(1) 105B + 42He → 137N + 10n
(3) S + 2e– → S2–
(2)
14
6C
→ 147N + −10e
(4) Na → Na+ + e–
13. Given the equation representing a nuclear reaction in which X represents a nuclide:
232
4
90Th → 2He + X
Which nuclide is represented by X?
(1) 236
(2) 228
(3) 236
(4) 228
92Ra
88Ra
92U
88U
14. Every chlorine atom has
(1) 7 electrons
(2) 17 neutrons
(3) a mass of 35
(4) an atomic number of 17
15. The diagram below represents the bright line spectra of four elements and a bright line spectrum
produced by a mixture of three of these elements.
Which element is not present in the mixture?
(1) Element A
(2) Element D
(3) Element X
(4) Element Z
16. Compared to the mass and the penetrating power of an alpha particle, a beta particle has
(1) less mass and greater penetrating power (3) more mass and greater penetrating power
(2) less mass and less penetrating power
(4) more mass and less penetrating power
17. An atom in the ground state has two electrons in its first shell and six in its second shell. What is
the total number of protons in the nucleus of this atom?
(1) 5
(2) 2
(3) 7
(4) 8
18. A bromine atom in an excited state could have an electron configuration of
(1) 2–8–18–6
(2) 2–8–18–7
(3) 2–8–17–7
(4) 2–8–17–8
19. The atomic masses and the natural abundances of the two naturally occurring isotopes of lithium
are shown in the table below
Which numerical setup can be used to determine the atomic mass of lithium?
(1) (0.075)(6.02 u) + (0.925)(7.02 u)
(3) (7.5)(6.02 u) + (92.5)(7.02 u)
(2) (0.925)(6.02 u) + (0.075)(7.02 u)
(4) (92.5)(6.02 u) + (7.5)(7.02 u)
20. A solid element that is malleable, a good conductor of electricity, and reacts with oxygen is
classified as a
(1) metal
(2) metalloid
(3) noble gas
(4) nonmetal
21. What is the oxidation number of iodine in KIO4?
(1) +1
(2) –1
(3) +7
(4) –7
22. Which compound has the smallest percent composition by mass of chlorine?
(1) HCl
(3) LiCl
(2) KCl
(4) NaCl
23. In the compound KHSO4, there is an ionic bond between the
(1) KH+ and the SO42– ions
(3) K+ and the HS– ions
(2) KHSO3+ and the O2– ions
(4) K+ and the HSO42– ions
Base your answers to questions 24 and 25 on the information below.
Information about Two Mixtures at 20.°C
Group 1
Particle
Group 17
Radius (pm)
Li atom
Li+ ion
Na atom
Na+ ion
K atom
K+ ion
Rb atom
Rb+ ion
130.
78
160.
98
200.
133
215
148
Particle
F atom
F– ion
Cl atom
Cl– ion
Br atom
Br– ion
I atom
I– ion
24. The radius of a bromine ion is approximately
(1) 117 pm
(2) 181 pm
Radius (pm)
60.
133
100.
181
117
?
136
220.
(3) 195 pm
(4) 221 pm
25. The name and the charge of the particle gained by a fluorine atom when the fluorine atom
becomes an ion are
(1) neutron, 0
(2) positron, +1
(3) proton, +1
(4) electron, –1
26. What is the name of the sodium salt of phosphoric acid?
(1) sodium hypophosphite
(3) sodium phosphide
(2) sodium phosphate
(4) sodium phosphite
27. Which formula is also an empirical formula?
(1) CH4
(2) H2O2
(3) C4H10O2
(4) C3H6O3
28. What is the name of the compound with the formula N2O5?
(1) nitrogen (V) oxide
(2) nitrogen (II) oxide
(3) nitrogen (III) oxide
(4) nitrogen (IV) oxide
29. What is the total number of atoms represented by the formula BaCl2 ∙ 2H2O?
(1) 5
(2) 8
(3) 9
30. Which is the correct formula for iron (II) oxide?
(1) FeO2
(2) FeO
(3) Fe2O3
(4) 18
(4) Fe3O4
31. Which element is brittle in the solid phase and is a poor conductor of heat and electricity?
(1) calcium
(2) strontium
(3) sulfur
(4) copper
32. Polar covalent bonds are caused by
(1) unbalanced ionic charges
(2) unequal electronegativity values
(3) the transfer of electrons between atoms
(4) equally shared valence electrons
33. Which compound has the strongest hydrogen bonding between its molecules?
(1) HBr
(2) HCl
(3) HF
(4) HI
34. Which kind of energy is stored in a chemical bond?
(1) potential energy
(3) activation energy
(2) kinetic energy
(4) ionization energy
35. Which type of solid does pure water form when it freezes?
(1) ionic
(2) network
(3) metallic
(4) molecular
B. Short Answer.
Base your answers to questions 36 through 38 on the information below and on your knowledge
of chemistry.
The balanced equation below represent a reaction.
O2 (g) + energy → O (g) + O (g)
36. Identify the type of chemical bond in a molecule of the reactant.
double bond or nonpolar covalent bond _____________________________________________
37. In the space to the right, draw a Lewis
electron-dot diagram of one oxygen atom.
38. Explain, in terms of bonds, why energy is absorbed during this reaction:
Bond breaking always requires energy _______________________________________________
_______________________________________________________________________________
Base your answers to questions 39 through 42 on the information below and on your knowledge
of chemistry.
Before atomic numbers were known, Mendeleev developed a classification system for the 63
elements known in 1872 using oxide formulas and atomic masses. He used an R in the oxide
formulas to represent any element in each group. The atomic mass was listed in parentheses after
the symbol of each element. A modified version of Mendeleev’s classification system is shown in
the table below.
39. Identify one characteristic used by Mendeleev to develop his classification system of the
elements.
Oxide formulas. or Atomic masses. _________________________________________________
40. Based on Mendeleev’s oxide formula, what is the number of electrons lost by each atom of the
elements in Group III?
Three electrons are lost by each atom._______________________________________________
41. Based on Table J, identify the least active metal listed in Group I on Mendeleev’s table.
According to Table J, silver (Ag) is the least active metal in Group I. ________________________
42. Explain, in terms of chemical reactivity, why the elements in Group 18 on the modern Periodic
Table were not identified by Mendeleev at that time.
Mendeleev based his table on oxide formulas and Group 18 elements do not form oxides. _____
Base your answers to questions 43 through 45 on the information below and on your knowledge
of chemistry.
The ionic radii of some Group 2 elements are given in the table below.
Ionic Radii of Some Group 2 Elements
Symbol
Atomic
Number
Ionic
Radius (pm)
Be
4
44
Mg
Ca
Ba
12
20
56
66
99
134
43. On the grid above, mark an appropriate scale on the axis labeled “Ionic Radius (pm)”.
44. On the grid above, plot the data in the Ionic Radii table.
45. Strontium (Sr) is also in Group 2. Estimate the radius of strontium on the graph above.
Sr ≈ 116 ____________ pm