Wow, I really don't get this chemistry question. Help please?

Question

Ok, it says:

Using the periodic table entry below, match the phrases with their corresponding values.

http://media01.owotw.com/ipc_2008/2/molybdenum.gif

1. atomic number

2. atomic mass

3. number of valence electrons

4. number of electrons in the n = 3 shell

5. number of neutrons

Choices: 18, 54, 96, 42, 1.

Which goes to which? This makes no sense to me.

Answer 1

Mo was the element

atomic number was given as 42

atomic mass was given as 95.94

electron configuration was given as 2 8 18 13 1

Look at the periodic table entry again.

If you understand the numbers on the periodic table it makes sense.

42 is the atomic number so the number of protons = 42

Since the atomic mass is 95.94 the number of neutrons must be 96.94 - 42 = 54 (53.95 but 54 is the closest answer possibilty)

n=1 shell can hold 2 electron, n=2 shell can hold 8 electrons, the next number (18) must be the number of electrons in Mo's n=3 shell. The 13 is the number of electrons in the n=4 shell and the 1 is the number of electrons in the n=5 shell.

All of the numbers have been assigned except for the number 1. It can be assigned to the number of valence electrons.

1. atomic number = 42

2. atomic mass = 96 (95.94)

3. number of valence electrons = 1

4. Number of electrons in the n=3 shell = 18

5. Number of neutrons = 54  (96-42=54)