The Periodic Table [Continuing...]

In most Periodic Tables, only the atomic mass and atomic number are given. Therefore, one must calculate the number of neutrons since they are not stated directly.

In order to do this, you subtract the atomic number from the atomic mass.

For example:

Oxygen (O) has an average atomic number 8, but an atomic mass of 16. The number of protons then is 8. Since the atomic mass is the number of protons plus neutrons, we can subtract 8 from the atomic mass (16).

Thus, 16 - 8 = 8.

Therefore, Oxygen has are 8 neutrons..

As you get more acquainted with chemistry, the Periodic Table will be your "key" to solving problems.

Click the link below for an interactive Periodic Table.

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