Answer
(a) The green box is a transition metal.
(b) The blue box is an alkali metal.
(c) The yellow box is a halogen.
Work Step by Step
(a) The element corresponding to the green box is gold. Elements in groups 3 through 12 are called the transition metals.
(b) The element corresponding to the blue box is sodium. Elements in group 1 are called alkali metals.
(c) The element corresponding to the yellow box is chlorine. Elements in group 17 are called halogens.
