Question

mention the basic tendency of an atom which makes it to combine with other atoms?

Answer 1

The basic tendency of an atom which makes it to combine with other atoms is its valency.
Every atom tries tu o become stable in order to achieve nobel gas configuration. For this it forms chemical bonds with other atoms to share their electrons and ultimately becomes stable.

Answer 2

The basic tendency of atoms is to attain the nearest noble gas configuration in its outermost shell and become stable

Each and every element has only aim either they make bondings with each other or anything else they perform . They only want to have a stable octet configuration just like the noble gases ....