## Chemistry and Chemical Reactivity (9th Edition)

a) Main group metals in the chart: Li, Be, Na, Mg, Al, K, Ca. From these the most abundant is Magnesium (Mg) with $10^8$ relative abundance. b) Nonmetals in the chart: H, He, C, N, O, F, Ne, P, S, Cl, Ar. From these the most abundant is Hydrogen (H) with $10^{12}$ relative abundance. c) Metalloids in the chart: B, Si. From these the most abundant is Silicon (Si) with $10^8$ relative abundance. d) Transition metals in the chart: Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn. From these the most abundant is Iron (Fe) with $10^8$ relative abundance. e) Halogens in the chart: F, Cl. From these the most abundant is Chlorine (Cl) with $10^6$ relative abundance.