Question

Which of the following atom is largest in size and which one has least value of ionization
energy: Na, K, Mg and Ca? Justify.​

Answer 1

Answer:

K(Potassium)

Explanation:

Since the atomic size of an element decreases across a period and increases down a group, the atomic size of Potassium is larger than Calcium, Sodium and Magnesium.

Similarly, the Ionization Potential increases across a period and decreases down a group, so since Potassium is in Group 1, and Period 4, its I.P is lesser than that of the other three.

Answer 2

Answer:

Explanation:

Potassium should have largest size .. simply because K lies in group 1 and Ca lies in group 2 but they lie in the same period .. as we know that along the period atomic size decreases.. so K has largest size ... size of k is approximately 2.03 angstrom and that of Ca is 1.74 ...

And Mg should have high ionization energy because we know that ionization energy is inversely proportional to the atomic size .. so among the given elements Mg has smaller radius .. so it should have high ionization energy.. so Potassium have low IP