Which of the following statements about alkali metals is true?

alkali metals have full valence shells

alkali metals form 1- cations

alkali metals are very reactive

alkali metals form 2- cations

OPTION C, Alkali metals are more reactive.

Explanation:

Since alkali or IA group elements are more electropositive and they readily loose Electrons to form monocation. Hence they are very reactive.

Their valency shell configuration is ns1, incomplete.

They forms only monocations like Na+, K+ etc

Alkaline earth metals forms +2 ions

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