What is covalent bond? Give two examples.
Matter is anything that has mass and volume ( i.e. occupies space). Its SI unit is mole (mol).
The combining capacity of an atom or a radical is called its valency. It is also defined as the number of electrons transferred, received or shared by atoms or radicals during chemical reaction.
An atom in its ground state contains equal number of electrons and protons. The magnitude of charge of both electrons and protons are equal. However, their nature of charges are opposite. Thus, they cancel each other's effect. As a result, an atom is electrically neutral.
Atoms that are stable by following duplet or octet rule are called inert gases. For example: Helium (He), Neon (Ne), Argon (Ar), etc.
Their outermost shell is already fulfilled by maximum number of accomodable electrons. Hence, they show no reactivity towards chemical reaction. Thus, they are regarded inert.
The chemical bond formed by the transfer of electron from more electropositive atom to a more electronegative atom is defined as ionic bond.