In metal reactivity series, the more reactive metals are at

1. top
2. bottom
3. middle
4. none

Hydrogen is responsible for producing

1. heat and light
2. hydrogenated oil
3. fertilizers
4. all of the above

Water gas is a mixture of

1. carbon monoxide and oxygen
2. carbon monoxide and hydrogen
3. hydrogen and oxygen
4. hydrogen and nitrogen

Assertion (A): On the earth, hydrogen is mostly found in the form of compounds.

Reason (R): Hydrogen is a highly reactive element.

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.