What is the number of $$\mathrm{sp}^3$$ hybrid carbon atoms in $$\mathrm{HO}\left(\mathrm{CH}_2\right)_3 \mathrm{CH}\left(\mathrm{CH}_3\right) \mathrm{CH}\left(\mathrm{CH}_3\right)_2$$ ?

Which from following thermodynamic properties is a path function?

Which among the following species is reduced by tin easily?

Which from following combinations is an example for construction of n-type semiconductor?