Answer
(a) Mg, magnesium
(b) Kr, krypton
(c) Fr, francium
(d) I, iodine
Work Step by Step
(a) Elements in the same period are in the same row on the periodic table. We want to find the element that is in the alkaline earth metals (group 2A) that is in the same row as sulfur. That element is Mg or magnesium.
(b) Elements in the same period are in the same row on the periodic table. We want to find the element that is in the noble gases group (group 8A) and in the same row as potassium. That element is Kr or krypton.
(c) The alkali metals are group 1A of the periodic table. The lightest elements are toward the top and the heaviest elements are on the bottom of that column. The heaviest alkali metal is Fr or francium.
(d) Elements in the same period are in the same row on the periodic table. We want to find the element that is in the halogen group (group 7A) and in the same row as tin. That element is I or iodine.
