The isotopes of hydrogen and their mass ratio are -

1. Protium, Deuterium, Tritium ; 3:2:3

2. Protium, Deuterium, Tritium ; 1:2:3

3. Protium, Deuterium, Tritium ; 2:2:3

4. Protium, Deuterium, Tritium ; 3:2:1

Hydrogen exists in diatomic form rather than monoatomic form under normal conditions -

1. Due to high ionization enthalpy

2. Due to low ionization enthalpy

3. Due to high electron gain enthalpy

4. Due to low electron gain enthalpy

The consequences of high enthalpy of H–H bond in dihydrogen is /are :

The catalyst used to increase the production of H₂ , by ‘coal gasification' process is -

1. Copper 

2. FeCr₂O₄ (iron chromate) 

3. Pd/C 

4. None of the above.

Hydrogen is placed separately in the periodic table because : 

1. It resembles alkali metals.

2. It shows the same reactions as halogens.

3. Both (1) and (2)

4. None of the above.