For Group 2A metals, which electron is the most difficult to remove? the second the first the third All the electrons are equally difficult to remove.

the third

Explanation:

when you remove the first the nucleur attraction becomes greater pulling the other valence electron closer thus the more you remove the harder it gets because the pull from the nucleus increases.

you need to take a look at the periodic system in order to sort these elements into pairs that would most likely exhibit similar chemical properties. first, you need to find elements that are found in the same group (groups are vertical in the periodic system), and then to see whether they have the same valence number. if they meet these criteria, they will have similar properties.

the first pair: ne (neon) and kr (krypton), are noble gases found in group 8

the second pair: li (lithium) and k (potassium), found in group 1

the third pair: s (sulfur) and te (tellurium), found in group 6