The molecules of alkene family are represented by a general formula CnH2n. Answer the following: (a) What do n and 2n signify? (b) What is the name of alkene when n = 4? (c) What is the molecular formula of alkene when n = 4? (d) What is the molecular formula of the alkene if there are ten H atoms in it? (e) What is the structural formula of the third member of the alkene family? (f) Write the molecular formula of lower and higher homologous of an alkene which contains four carbon atoms.