ICSEClass XChemistryPeriodic Table, Periodic Properties and Variations of Properties03 Mark2026 Moderate

QQuestion

Given below are a few elements.

Li, Li, K, Ca, F

Identify the element which:

(a) has the least atomic radius.

(b) has two valence electrons.

(c) is the most electropositive.

Exam-ready answer 03 Mark

Answer

(a) Fluorine (F)

(b) Calcium (Ca)

(c) Potassium (K)

Explanation –

(a) Fluorine (F) has the least atomic radius. It is on the rightmost side of period 2, where atomic radius is minimum.

(b) Calcium (Ca) has two valence electrons (electronic configuration: 2, 8, 8, 2). It belongs to Group 2 of the periodic table.

(c) Potassium (K) is the most electropositive. Within Group 1, electropositive character increases down the group; potassium is below lithium and hence is more electropositive.

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