Electronic configuration of four elements A, B, C and D are given below :

(A) $1 s^2 2 s^2 2 p^3$

(B) $1 s^2 2 s^2 2 p^4$

(C) $1 s^2 2 s^2 2 p^5$

(D) $1 s^2 2 s^2 2 p^2$

Which of the following is the correct order of increasing electronegativity (Pauling's scale)?

A tetrapeptide, " $x$ " on complete hydrolysis produced glycine (Gly), alanine (Ala), valine (Val), leucine (Leu) in equimolar proportion each. The number of tetrapeptides (sequences) possible involving each of these amino acids is :

Which among the following molecules is (a) involved in $\mathrm{sp}^3 \mathrm{~d}$ hybridization, (b) has different bond lengths and (c) has lone pair of electrons on the central atom?

In 3,3-dimethylhex-1-en-4-yne, there are _________$\mathrm{sp}^3$,_________$\mathrm{sp}^2$ and_________ sp hybridised carbon atoms respectively.