Question

Define atomic number and mass number. ​

Answer 1

Answer:

Atomic Number

The number of protons in the nucleus is called the atomic number of an element. It is also equal to the number of electrons in the orbits.

It is represented by Z.

Mass Number

The sum total of protons and neutrons in the nucleus is called the mass number of the element.

It is represented by A.

Answer 2

Heya Buddy ...

Atomic number -:

The number of electrons or protons in an atom is atomic number and it is a fundamental feature of element which helps you to tell about elements chemical properties..

Atomic mass.. -:

The sum of atomic number and no of neturons in an atom is atomic mass. it is fundamental feature which helps us determine physical properties.

Hope it helps ☺☺