Which statement is not true?

a. the atomic radius of na is less than the atomic radius of mg.
b. the electronegativity of c is greater than the electronegativity of b.
c. the ionic radius of br- is greater than the atomic radius of br.
d. the first ionization energy of k is greater than the first ionization energy of rb.

The statement that's isn't true is that A. atomic radius of Na is less than the atomic radius of Mg.

It should be noted that the electronegativity of C is greater than the electronegativity of B and that the ionic radius of Br- is greater than the atomic radius of Br.

On the other hand, the atomic radius of Na is not less than the atomic radius of Mg. Magnesium atom is smaller than that of sodium. The nuclear charge of magnesium is 12+ while that of sodium is 11+.

In conclusion, the correct option is A.

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D.

Explanation:

D. The first ionization energy of K is greater than the first ionization energy of Rb.

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