Imagine your homework assignment involves identifying an unknown pure substance. the valence electrons of the substance's atoms feel an effective nuclear charge of +1. if this substance's atoms have larger radii than potassium (k) atoms, what other characteristics would you expect the substance to exhibit?
it would have higher ionization energies than k and a higher electronegativity value than k.

a.) it would have higher ionization energies than k and a lower electronegativity value than k.

b.) it would have lower ionization energies than k and a higher electronegativity value than k.

c.) it would have lower ionization energies than k and a lower electronegativity value than k.

d.) it would have higher ionization energies than k and a higher electronegativity value than k

The correct answer is (c)  It would have lower ionization energies than K and a lower electronegativity value than K

Explanation- The unknown element belongs to the alkali metals of periodic table. The alkali metal atoms have the largest size in a particular period of the period of periodic table. With the increase in the atomic number, the atom becomes larger.

Atomic radius decreases --> ionization energy increase>Electronegativity increases. We can use this flow chart to compare the  IE and EN of the element. As K have lower radii than the unknown element, so the IE and EN of K will be  greater  than the unknown element.

The correct answer is Option c.

Explanation:

It is given that the valence electrons of the substance's atoms feel an effective nuclear charge of +1 and its radii is larger than the Potassium atoms.

The elements which belong to group 1 shows an effective nuclear charge of +1. Therefore, the given substance also belongs to group 1.

In a group, the ionization energy decreases as we move down the group as the size increases and thus the valence shell moves farther from nucleus and thus is easier to remove.

Electronegativity also decreases as we move down the group as the size increases, thus the affinity for incoming electron decreases.

Hence, the correct answer is Option c.