Electronegativity generally decreases as atomic radius increases, and it is lower for elements that have fewer valence electrons, especially those in groups 1 and 2 of the periodic table.
Among the responses provided:
- An element with a small number of valence electrons and a large atomic radius would likely have the lowest electronegativity. This is because elements with fewer valence electrons (such as alkali metals) typically do not attract electrons strongly, and a larger atomic radius means that the nucleus is further away from the valence electrons, making it less effective in attracting additional electrons.
Therefore, the correct choice is:
an element with a small number of valence electrons and a large atomic radius.