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): Magnesium burns in oxygen to produce a compound magnesium oxide with the molecular formula MgO.

Reason (R): Magnesium oxide is a white amorphous solid.

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.

Fill in the blanks:

(a) A symbol represents …………… of an element.

(b) An atom is neither created nor destroyed during a …………… .

(c) …………… are positively charged ions.

(d) Total number of atoms of all the elements present in Al₂O₃ is …………… .

(e) A …………… is the symbolic representation of a chemical reaction using symbols and formulae of the substances taking part in the reaction.