Assertion (A): When an atom gains one or more electrons, it becomes negatively charged.

Reason (R): The number of electrons in an atom exceeds the number of protons upon gaining electrons.

1. Both A and R are true and R is the correct explanation of A.
2. Both A and R are true but R is not the correct explanation of A.
3. A is true but R is false.
4. A is false but R is true.

Assertion (A): Each element has its own unique symbol, which is a short hand representation of its atom.

Reason (R): The symbol of some elements is the same as the first letter of their names.

1. Both A and R are true and R is the correct explanation of A.
2. Both A and R are true but R is not the correct explanation of A.
3. A is true but R is false.
4. A is false but R is true.

Assertion (A): The valency of inert gases, helium, neon and argon is zero.

Reason (R): The outermost shell of inert gases is complete.

1. Both A and R are true and R is the correct explanation of A.
2. Both A and R are true but R is not the correct explanation of A.
3. A is true but R is false.
4. A is false but R is true.

Assertion (A): A chemical equation is the symbolic representation of a chemical reaction using symbols and formulae of the substances involved in the reaction.

Reason (R): Every chemical equation needs to be balanced to follow the law of conservation of mass.

1. Both A and R are true and R is the correct explanation of A.
2. Both A and R are true but R is not the correct explanation of A.
3. A is true but R is false.
4. A is false but R is true.