Answers to UNIT 3 Self Test:

1.  b: Calcium is in group IIA and in the forth row meaning that its outermost configuration would be 4s².

2.  d: These four elements are all in the same group.

3.  c: Cs is in the lower left hand corner of the periodic table where I.E.s are lowest.

4.  a: Group # 5A indicates that 5 electrons are in the outermost filling energy level.

5.  b: negative ions have gained an electron but not a proton, thus they are larger than their atom.

6.  c: Fe is a transition metal and is in the "d" block.

7.  c: F neutral atoms are smaller than their negative ions and F is smaller than Li since they are in the same period.

8.  a: As one goes down a group the valence electrons are filling higher energy levels and are farther from the nucleus.

9.  b: electrons in the same energy level are held by increasing number of protons as Z increases.

10.  c: Ca has two valence electrons.  When these two are removed the third electron must be taken from a lower energy level which requires a significantly greater amount of energy.

11.  a. fluorine    b. magnesium    c. oxygen    d. silicon

12.  a. gallium    b. oxygen    c. chlorine

13.  Ionization energy (IE) increases up a group and from left to right across a period.  The reason for the increasing amount of energy required to remove an electron from an atom is related to the size of the atom.  The smaller the atom, the more tightly the electrons are drawn to the nucleus.  When the electrons are more tightly held, they require more energy to remove them, hence the trend up a group.  Within a period atomic radius (AR) tend to decrease from left to right.  As the AR decreases, the outermost electrons are held more tightly.  Therefore, they require a greater IE to remove them, hence the trend.

14.  a.  15, VB, 5A    b. 11, IB, 1B    c. 18, VIIIB, 8A 

15. a. metal    b. non-metal    c. semimetal    d. metal

16.  Columns 1 and 2 form the "s-block" and columns 13-18 form "p-block."  These two blocks contain the "representative elements."  Columns 3-12 form the "d-block" which are called the "transition metals."  The two rows that are placed below the main body of the periodic table compose the "f-block" and they are called "inner transition metals."

17.  1A - Alkali Metals    2A - Alkaline Earth Metals    7A (17) - Halogens    8A (18) - Noble Gases    [Other names: 11 - coinage metals, 15 - pnicogens, 16 - chalcogens