The element from group 15 that forms a strong bond with hydrogen is:

PH₃ forms bubbles when passed slowly through water but NH₃ gets dissolved in water, because: 

The bonding present in nitrogen molecules is:
1. $p\pi-p\pi$
2. $p\pi-d\pi$
3. $d\pi-d\pi$
4. Only sigma bond

An element that does not have a d-orbital is:

NH₃ forms a hydrogen bond but PH₃ does not because:  

 Match the formulas of oxides given in Column I with the type of oxide given in Column II and mark the correct option.

Codes

The respective oxidation states of P in H₄P₂O₅, H₄P₂O₆, and H₄P₂O₇ are: 

A balanced chemical equation for the reaction showing catalytic oxidation of NH₃ by atmospheric oxygen is:

An element belongs to group 15 and 3^rd period of the periodic table. Its electronic configuration would be:
1. $\mathrm{1 s^2 2 s^2 2 p^4}$
2. $\mathrm{1 s^2 2 s^2 2 p^3}$
3. $\mathrm{1 s^2 2 s^2 2 p^6 3 s^2 3 p^2}$
4. $\mathrm{1 s^2 2 s^2 2 p^6 3 s^2 3 p^3}$

Nitrogen gas is liberated by the thermal decomposition of:

1. ${\mathrm{NH}}_4{\mathrm{NO}}_2$                                 

2. ${\mathrm{NaN}}_3$

3. ${\left({\mathrm{NH}}_4\right)}_2{\mathrm{Cr}}_2{\mathrm{O}}_7$                           

4. All of the above.