The compounds with $sp^2$ hybridized central atom among the following are:
$(A)$ $H_2CO_3$
$(B)$ $SiF_4$
$(C)$ $BF_3$
$(D)$ $HClO_2$

The shape of $CH_3^+$ species is

Which one of the following statements is true for the ammonium ion $(NH_4^+)$?

Which of the following statements is true regarding the $PCl_5$ molecule?
$(i)$ The two axial $P-Cl$ bonds in $PCl_5$ are longer than the three equatorial bonds.
$(ii)$ The axial bonds in $PCl_5$ are stronger than equatorial bonds.
$(iii)$ The axial bonds in $PCl_5$ are more stable than equatorial bonds.
$(iv)$ All five bonds in $PCl_5$ molecule are equivalent.

What is $sp^{2}$ hybridization? Give its characteristics.

How many $sp^2$ and $sp$ hybridized carbon atoms are present respectively in the following compound? (The structure is $1,2-didehydrobenzene$ or $benzyne$ derivative,specifically $1,2-didehydrocyclohexadiene$ structure shown in the image).