Question

select the correct answer. which of these 2a elements has the largest atomic radius? a. beryllium b. magnesium c. calcium d. barium e. radium

Explanation:

Atomic radius increases down a group in the periodic table. Among the Group 2A (alkaline - earth metals) elements beryllium (Be), magnesium (Mg), calcium (Ca), barium (Ba), and radium (Ra), radium is at the bottom - most position in the group. So it has the largest atomic radius due to the addition of more electron shells as we move down the group.

Answer:

E. radium