Among the alkali earth metals, the tendency to react with other substances <span>increases from bottom to top within the group. We know that when there is an increase of metallic property, there will also be an increase of reactivity. So the answer is letter A.</span>
Answer: option <span>A) increases from bottom to top within the group.
Explanation:
</span>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.
<span>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.</span>
The electron cloud is an informal term in chemistry and physics. This region describes the negatively charged electrons in their orbit surrounding the nucleus in an atom. The nucleus has protons in it that have a positive charge on it. It is not easy to know where exactly an electron in any specific time but the electron cloud helps to know electron is moving in this specific area.