Chemistry
Atoms and the Periodic Table
Name_________________________
Goal: To be able to identify the number of protons, neutrons and electrons in a neutral atom
from the information provided in the Periodic Table.
Finish the table below. For the purpose of this exercise, round the average atomic mass on the
Periodic Table to the nearest whole number to determine the mass number.
Remember: number of neutrons = mass number – atomic number (number of protons)
Name
Symbol
Atomic
Number
Mass
Number
Number
of
Protons
Number
of
Neutrons
Number
of
Electrons
Calcium
Hydrogen
Carbon
Bromine
Aluminum
Lithium
Barium
Oxygen
9
2
11
Potassium
Cl
56
Chromium
92
Nitrogen
6
5
Zn
10
32
12
47
Gold
28
55