In what respect does hydrogen differ from

(i) Alkali metals

(ii) Halogens

Give the general group study of hydrogen with reference to:

(i) valence electrons

(ii) burning

(iii) reducing power.

State some sources of hydrogen.

Compare hydrogen and halogens on the basis of :

(i) Physical state

(ii) ion formation

(iii) valency

(iv) reaction with oxygen