Which two of the following elements would you expect to be most similar: nitrogen, chlorine, barium, fluorine, and sulfur?

Chlorine and Flourine

Explanation:

It is important to identify the groups in which the elements being to. The elements in each group have the same number of electrons in the outer orbital. Those outer electrons are also called valence electrons.

Since elements in a group have the same number of valence electrons, they behave similarly in chemistry.

Nitrogen - Group 5

Chlorine - Group 7

Barium - Group 2

Flourine - Group 7

Sulphur - Group 6

This means the most similar elements would be flourine and Chlorine because they are both group 7 elements.

indium, and thallium have three electrons i think

what is the question here. i think you messed up.