Question

1. use a periodic table to choose the best answer.

which of these elements has a lower electronegativity?
i
na
rb
k

1. use a periodic table to choose the best answer.

____ would have an electron affinity higher than that of oxygen.
be
ca
u
f

Explanation:

2.

Electronegativity generally increases across a period and decreases down a group. Among the given elements, \(Rb\) is the furthest down the group (Group 1) compared to \(Na\) and \(K\), and \(I\) is in a different group (Group 17). Since electronegativity decreases down a group, \(Rb\) has a lower electronegativity.

Electron affinity generally increases across a period (except for some irregularities). Fluorine (\(F\)) is to the right of oxygen (\(O\)) in the same period (Period 2). As we move from left to right across a period, electron affinity tends to increase. Beryllium (\(Be\)) and calcium (\(Ca\)) are metals with lower electron affinities compared to non - metals like oxygen and fluorine. Uranium (\(U\)) is a heavy metal with a very low electron affinity.

Answer:

Rb

3.