Answer:
Atom's chemical properties are determined by the number of electrons in its outermost shells.
Based on the number of electrons in the shells, it decides the reactivity of atoms. Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â
Atoms with same number of electrons in the outer shells have similar chemical properties.
If atoms have 1,2 or 3 valence electrons they react by giving out those electrons to become stable. If atoms have 6 or 7 electrons in the outer shell they react by taking in electrons to complete its outer shell.
