Question

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

Explanation:

• Representative elements are the elements in groups 1, 2, and 13 - 18 of the periodic table.
• Let's check each option:
• Option 1: Hg (Mercury), Cr (Chromium), Ag (Silver)
• Hg is a transition metal (group 12), Cr is a transition metal (group 6), and Ag is a transition metal (group 11). So, this group does not contain only representative elements.
• Option 2: Al (Aluminum), Mg (Magnesium), Li (Lithium)
• Al is in group 13, Mg is in group 2, and Li is in group 1. All of these are representative elements.
• Option 3: Ni (Nickel), Fe (Iron), Zn (Zinc)
• Ni is a transition metal (group 10), Fe is a transition metal (group 8), and Zn is a transition metal (group 12). So, this group does not contain only representative elements.
• Option 4: Cu (Copper), Co (Cobalt), Cd (Cadmium)
• Cu is a transition metal (group 11), Co is a transition metal (group 9), and Cd is a transition metal (group 12). So, this group does not contain only representative elements.

Answer:

Al, Mg, Li