The equation below shows the reaction between element 'X' and dilute sulphuric acid.

X(s) + H₂SO₄ (aq.) ⟶ XSO₄ (aq.) + H₂ (g)

Which particles are responsible for conducting electricity in dilute sulphuric acid and compound XSO₄?

1. Electrons
2. Only positive ions
3. Only negative ions
4. Both positive and negative ions

Assertion (A): Dry hydrogen chloride gas is collected by the upward displacement of air.

Reason (R): Hydrogen chloride gas is lighter than air.

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

Element 'P' has electronic configuration 2,8,8,1. The number of chlorine atoms present in the chloride of 'P' is:

1. 2
2. 1
3. 3
4. 4

₁H² is an isotope of hydrogen. In the modern Periodic Table it will:

1. be placed before hydrogen
2. be placed after hydrogen
3. be placed at the same position as hydrogen
4. not have any position in the Periodic Table