Atomic Mass Uni || Atomic Mass:

 Atomic mass uni. Atomic mass. In this post we will learn about atomic mass uni and atomic mass. The atomic mass is defined as “the sum of protons and neutrons in an atom is called atomic mass”.  In simple words atomic mass is the number of protons and neutrons in the nucleus of an atom. We can also define atomic mass as “the mass of nucleus” as shown in figure below. It is represented by A.

The number of neutrons and number of protons in an atom are always equal but in some atoms they are different. Some examples are given below in table.

Elements	No of protons	No of neutrons	Atomic mass (A)
Oxygen	8	8	16
Hydrogen	1	0	1
Sodium	11	12	23

 

                                  figure. protons in red color and neutrons in blue color