(a)[1]
Define the term covalent bond.
(b(i))[1]
Identify the hybridisation state of the carbon atoms in a C=C bond in an alkene.
(b(ii))[2]
Draw labelled diagrams to show, in terms of orbital overlap, how the $\sigma$ and $\pi$ bonds are formed in a C=C bond.
(c(i))[1]
Suggest one difference between $\sigma$ and $\pi$ bonds that accounts for why the $\pi$ bond is broken in electrophilic addition reactions of alkenes.
(c(ii))[4]
Complete Fig. 5.1 to show the mechanism for the electrophilic addition of hydrogen bromide to 2-methylpropene that forms the major organic product. Add charges, dipoles, lone pairs of electrons and curly arrows where suitable.