Which of the following elements shows a stable $+2$ oxidation state?

Arrange the following in order of increasing dipole moment : $H_2O$,$H_2S$,$BF_3$.

In which of the following reactions does the hybridisation of the central atom change from $sp^2$ to $sp^3$?

Which of the following is a cationic detergent?

If $\tan \theta + \tan \left(\theta + \frac{\pi}{3}\right) + \tan \left(\theta + \frac{2\pi}{3}\right) = 3$,then which of the following is equal to $1$?

$A$ number $n$ is chosen at random from $\{1, 2, 3, 4, \ldots, 1000\}$. The probability that $n$ is a number that leaves remainder $1$ when divided by $7$ is: