Answer:
H2
Step-by-step 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.