Among the alkali earth metals, the tendency to react with other substances a) increases from bottom to top within the group. b) is shown by the ways they react with water. c) varies in an unpredictable way within the group. d) does not vary among the members of the group.

option A) increases from bottom to top within the group.

Explanation:

It is a known trend that the metallic character of the elements increase from let to right and from top to bottom.

The greater the metallic character the greater the reactivity of the metal.

So, the elements of the columns 1 and 2 are the most reactive metals and among them the elements at the bottom are yet more reactive.

The higher reactivity of the metals that are lower in the periodic table is attributed to the greater total number of electrons.

The greater the total number of electrons the more reactive the metals as their outermost electrons (the valence electrons which are those that react) are located further from the nucleus and therefore they are held less strongly, which makes them react more easily.

The answer options is d

Coal i believe hope this