Question

which group 2a element has the largest ionic radius?
a. magnesium
b. calcium
c. barium
d. radium

Explanation:

Step1: Understand ionic radius trend

Ionic radius increases down a group in the periodic table.

Step2: Analyze group 2A elements

Group 2A elements are \(Mg\), \(Ca\), \(Ba\), \(Ra\). As we move down from \(Mg\) (\(12^{th}\) element) to \(Ca\) (\(20^{th}\)), \(Ba\) (\(56^{th}\)), \(Ra\) (\(88^{th}\)), the number of electron shells increases.

Step3: Determine the largest ionic radius

Since \(Ra\) is the bottom - most element in group 2A among the given options (\(Mg\), \(Ca\), \(Ba\), \(Ra\)), it has the largest ionic radius.

Answer:

D. radium