Question

which of the following groupings contains only representative elements?
cu, co, cd
hg, cr, ag
ni, fe, zn
al, mg, li

Explanation:

Representative elements are in groups 1 - 2 and 13 - 18 of the periodic table.

• Cu (Copper), Co (Cobalt), Cd (Cadmium) are transition metals (groups 3 - 12).
• Hg (Mercury), Cr (Chromium), Ag (Silver) are transition metals.
• Ni (Nickel), Fe (Iron), Zn (Zinc) are transition metals.
• Al (Aluminum) is in group 13, Mg (Magnesium) in group 2, Li (Lithium) in group 1. All are representative elements.

Answer:

Al, Mg, Li