Answer:
H2
Explanation:
In the first place it is necessary to consider that these two elements will be their diatomic form initially, that is, H2 and N2.
first we should check the equilibrium constant Kp tables in this case at a temperature of 3000K
Value for dissociation reaction of H2 in Kp = -3.685
Value for dissociation reaction of N2 in Kp = -22.359
Equilibrium constant for H2 dissociation is higher than N2 dissociation. so for this comparation H2 is more likely to dissociate.
Answer: 1) only a salt and water
An acid and base reacts together to undergo neutralization to form salt and water.

where HCl is an acid and NaOH is a base to form salt (NaCl) and water
.
Answer: 2) The formula of the hydrogen ion is often written as
.
All acids dissociate in water to give
ions.
Answer: 3) Arrhenius acids are substances that ionizes to yield protons in aqueous solution.

Arrhenius bases are substance that ionizes to yield hydroxide ions in aqueous solution.

Answer: 4) A conjugate acid base pair transfers hydrogen ion.
Here
accepts a proton and thus act as a base and the corresponding
is its conjugate acid.
Answer: 5) Bronsted Lowry acid is a substance that donates protons. Bronsted Lowry base is a substance that accepts protons.
and 

is a acid which accepts proton and thus acts as base to form conjugate acid
.