Element a has one valence electron. how does its reactivity compare to that of element b, which has four valence electrons? a) element a is more reactive. b) element a is less reactive. c)element a and b have the same reactivity.

The correct answer is A) Element A is more reactive.

Explanation:

Valencia electrons are the electrons found in the last electronic layer (called valence orbitals). These electrons are what determine the ability of the atom to form bonds. When an element joins another, it does so through its valence electrons.

On the other hand, the octet rule states that the atoms of the elements bind each other in the attempt to complete their valence layer with eight electrons. That is to say, the atoms will tend to yield or share electrons to complete eight electrons in the valence layer through an ionic, covalent or metallic bond.

 Element A has a valence electron, which can easily give to another element to achieve stability.

However, element B has four valence electrons, which should transfer or gain another four electrons to achieve stability. This makes more energy required, being less reactive.

So, the correct answer is A) Element A is more reactive.