ATOMIC STRUCTURE WORKSHEET
Name
1. Complete the table. There is enough information given for each element to determine all missing numbers.
Symbol
23
Atomic
Number
Mass
Number
Number
of
Protons
Number
of
Electrons
Number
of
Neutrons
13
11
15
Na1+
K1+
40
F1-
10
26
51
25
50
50
72
131 1-
I
26
Mg2+
109
1
36
2
46
1
18
S
26
27
47
23
10
25
Al
2
Cr
4
2
53
2. Identify two different ions of the same isotope of the same element. What do they have in common? What is
different?
3. Identify two different isotopes of the same element? Are these two atoms or ions?
4. Draw two symbols for different ions of different isotopes of the same element?
5. Sketch a picture of a Carbon 13 (4- ion), showing the location of all subatomic particles.
6. The number of protons in one atom of an element determines the atom’s ____________________, and the number
of electrons determines the _________________________ of the element.
7. The atomic number tells you the number of ___________________________ in one atom of an element. It also tells
you the number of __________________________ in a neutral atom of that element. The atomic number gives the
“identity” of an element as well as its location on the periodic table. No two different elements will have the
____________________ atomic number.
8. The _______________________ of an element is the total number of protons and neutrons in the
___________________ of the atom.
9. The mass number is used to calculate the number of ______________________ in one atom of an element. In order
to calculate the number of neutrons you must subtract the ______________________ from the
10. If you know ONLY the following information can you ALWAYS determine what the element is? (Yes/No)
a. Number of protons ____________________________
b. Number of neutrons ___________________________
c. Number of electrons in a neutral atom ___________________________
d. Number of electrons _________________________
11. While every element is ____________________ (different or the same) from every other element…each element is
made up of _____________________________ which are ________________________ (different or the same)
between one element and another.