Number of compounds from the following with zero dipole moment is . . . . . .
$HF, H_2, H_2S, CO_2, NH_3, BF_3, CH_4, CHCl_3, SiF_4, H_2O, BeF_2$

Which molecule has a zero dipole moment?

Bond distance in $HF$ is $9.17 \times 10^{-11} \ m$. Dipole moment of $HF$ is $6.104 \times 10^{-30} \ Cm$. The percentage ionic character in $HF$ will be : .............. $\%$
(electron charge $= 1.60 \times 10^{-19} \ C$)

Choose the polar molecule from the following:

The compound that will have a permanent dipole moment among the following is

$H_2O$ is dipolar,whereas $BeF_2$ is not. It is because