Which of the following has the lowest boiling point?

$A$ bag contains $n$ white and $n$ black balls. Pairs of balls are drawn at random without replacement successively,until the bag is empty. If the number of ways in which each pair consists of one white and one black ball is $14400$,then $n$ is equal to

How many types of lichens are there based on their external morphology (growth form)?

The energy band diagrams for three semiconductor samples of silicon are as shown. We can then assert that

The reaction of $CH_3-CH=CH-C_6H_4-OH$ with $HBr$ gives:

If $f(x) = (x^2 - 1)^7$,then $f^{(14)}(x)$ is equal to