What is the hybridization of carbon in graphite and diamond,respectively?

What is the type of chemical covalent bond between the carbon-carbon atoms in $C_2H_4$?

Match List-$I$ with List-$II$ :

List-$I$ (Species)	List-$II$ (Hybrid Orbitals)
$(a)$ $SF_{4}$	$(i)$ $sp^{3}d^{2}$
$(b)$ $IF_{5}$	$(ii)$ $d^{2}sp^{3}$
$(c)$ $NO_{2}^{+}$	$(iii)$ $sp^{3}d$
$(d)$ $NH_{4}^{+}$	$(iv)$ $sp^{3}$
	$(v)$ $sp$

Choose the correct answer from the options given below :

Which orbital is more electronegative among $sp$,$sp^2$,and $sp^3$? Why?

Sulphur reacts with chlorine in $1:2$ ratio and forms $X$. Hydrolysis of $X$ gives a sulphur compound $Y$. What is the structure and hybridisation of the anion of $Y$?

The number of molecules/ions from the following in which the central atom is involved in $sp^3$ hybridization is: $NO_3^{-}, BCl_3, ClO_2^{-}, ClO_3$