Unit 3 Study Guide – Key
Honors Chemistry
Multiple Choice Answers:
1. b
6.
2. d
7.
3. c
8.
4. a
9.
5. b
10.
c
b
c
c
c
11.
12.
13.
14.
15.
d
b
d
a
d
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16.
17.
18.
19.
20.
c
b
c
c
b
21.
22.
23.
24.
c
b
d
a
25. According to Mendeleev: when the elements are arranged in order of increasing atomic mass, there is a
periodic repetition of their physical and chemical properties.
According to Moseley: when the elements are arranged in order of increasing atomic number, there is a
periodic repetition of their physical and chemical properties.
26. The difference between the periodic law of Mendeleev and Moseley is that Mendeleev arranged his
periodic table in order of increasing atomic mass and Moseley arranged his periodic table in order of
increasing atomic number.
27. The atomic radius is one-half the distance between the nuclei of two atoms of the same element when the
atoms are joined.
28. Ionization energy is the energy required to remove an outermost electron from an atom.
29. Electronegativity is the tendency of an atom to attract additional electron density from another atom to
which it is bound.
30. Fluorine has a smaller atomic radius than oxygen because there are more protons in the nucleus of fluorine
which draws the electrons closer which makes the atom smaller. Fluorine is smaller than chlorine because
the outermost electrons are at a lower energy level than the outermost electrons of chlorine. Therefore, the
electrons in fluorine are closer to the nucleus than are the electrons in chlorine.
31. Oxygen has a smaller atomic radius than nitrogen because there are more protons in the nucleus of oxygen
which draws the electrons closer which makes the atom smaller. Oxygen is smaller than sulfur because the
outermost electrons are at a lower energy level than the outermost electrons of sulfur. Therefore, the
electrons in oxygen are closer to the nucleus than are the electrons in sulfur.
32. Sodium has a lower ionization energy value than magnesium because there are fewer protons in the
nucleus of sodium which means that the electrons are not held as tightly as they are in magnesium.
Sodium has a lower ionization energy than lithium because the outermost electrons are at a higher energy
level than the outermost electrons of lithium. Therefore, the electrons in sodium are further away from the
nucleus than are the electrons in lithium. This makes the electrons of sodium easier to remove.
33. Fluorine has a higher electronegativity value than oxygen because there are more protons in the nucleus of
fluorine which draws the electrons closer which makes the atom smaller. This means that when fluorine
bonds to another atom, the electron cloud of the other atom will be closer to the fluorine nucleus than it
would be to the oxygen nucleus. Fluorine is smaller than chlorine because the outermost electrons are at a
lower energy level than the outermost electrons of chlorine. Therefore, the electrons in fluorine are closer
to the nucleus than are the electrons in chlorine. This means that when fluorine bonds to another atom, the
electron cloud of the other atom will be closer to the fluorine nucleus than it would be to the chlorine
nucleus.
Honors Chemistry
Unit 3 Study Guide – Key
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34. Rubidium has a lower electronegativity value than strontium because there are fewer protons in the
nucleus of rubidium which does not draw the electrons as close as the nucleus of strontium which makes
the rubidium atom larger. This means that when rubidium bonds to another atom, the electron cloud of the
other atom will be farther from the rubidium nucleus than it would be from the strontium nucleus.
Rubidium is larger than potassium because the outermost electrons are at a higher energy level than the
outermost electrons of potassium. Therefore, the electrons in rubidium are farther from the nucleus than
are the electrons in potassium. This means that when rubidium bonds to another atom, the electron cloud
of the other atom will be farther from the rubidium nucleus than it would be from the potassium nucleus.