Question 3 :
Which one of the following elements does not form the compound, M$_{4}$ O$_{10}$ (M = element)?<br/><br/>

Question 8 :
Nitrogen form $N_2$, but phosphorous form $P_2$, it'sat a time convert in $P_4$, reason is : -

Question 11 :
Give examples of compounds of N with oxidation number -3 .

Question 12 :
Assertion (A): Bismuth compounds are stable in&#160;+V oxidation state than in +III oxidation state.<br/>Reason (R): Inert pair effect is observed in Bismuth compounds.<br/>

Question 14 :
Assertion (A): The basic nature of VA group hy-drides decreases from ammonia to bismuthine.<br/>Reason (R): Availability of lone pair on the cen-tral atom in hydrides decreases down the group.<br/>

Question 18 :
Nitrogen and phosphorus are both in Group 15 of the Periodic Table. Phosphorus forms a chloride with the formula $P{Cl}_{5}$ but nitrogen does not form $N{Cl}_{5}$.<br>Which statements help to explain this?<br>1. Nitrogen's outer shell cannot contain more than eight electrons.<br>2. Nitrogen cannot have an oxidation state of $+5$<br>3. Nitrogen is less electronegative than phosphorus.