Question

Consider the following neutral electron configurations in which 'n' has a constant value. Which configuration would belong to the element with the most negative electron affinity, E-ea?

a) ns^2

b) ns^2 np^2

c) ns^2 np^5

d) ns^2 np^6

would the answer be "d"??? (as in, it would be a noble gas with a p^6, and then have a more negative e- affinity???)

Answer 1

If it is a noble gas, it has no affinity to attract an additional electron. I would examine the affintity of c) (as Fluorine, chlorine ).

Answer 2

Unless I am out of date or misunderstood the question I thought that all electron affinities were shown as positive values. Those ending np^5 (e.g fluorine or chlorine) have the highest electron affinities.

Answer 3

The electron affinity is defined as the amount of energy ABSORBED when an electron is added to an isolated gaseous atom to form an ion with a 1- charge. The convention is to assign a positive value when energy is absorbed and a negative value when energy is released. For example, Be(g) + e + 241 kJ ==> Be^-(g) EA = +231 kJ/mol. (endothermic)

Cl(g) + e ==> Cl^-(g) + 348 kJ/mol EA = -348 kJ/mol (exothermic)

I think c is the answer.

Answer 4

The answer is c) ns^2 np^5

I know this because in addition to the explanations posted, above I just did this for my chemistry homework. I'm guessing you also have Mastering Chemistry?