Page 3 - classification of elements

The number of electrons, protons and neutrons

in different atoms are different.

The number of proton or electron in atom

gives the characteristic

called atomic number.

:. Atomic number (z)= no. of proton= no. of electron

+
Z=p =e -

The sum of numbers of protons and numbers of neutrons

present in nucleus of an atom is called atomic weight.

:. Atomic weight (A)= no. of protons + no. of neutrons

+
A = p + n 0