What is the Atomic Mass of Phosphorus?

Atomic Mass of Phosphorus is  .

A) 30

B) 28

C) 31

D) 32

Answer:

Option C) 31 is correct.

Explanation:

Atomic Mass of any substance is the sum of the number of protons and the number of neutrons in the nucleus of that atom.

For Phosphorus,

• Number of Protons = 15
• Number of Neutrons = 16

Thus,

Atomic Mass of Phosphorus = 15 + 16 = 31

In absolute terms, the average atomic mass of Phosphorus is 30.973762 amu. It is calculated taking into account all the isotopes of Phosphorus.

The three main Isotopes of Phosphorus are listed below:

• ³¹P  (Stable)
• ³²P
• ³³P

There are more than 20 known isotopes of Phosphorous and the only stable isotope of Phosphorous, i.e. ³¹P. Apart from this the other important isotope of Phosphorous, are ³²P, and ³³P.