Question

Why is radium more reactive than calcium?

A. Radium has more protons.
B. Radium has fewer neutrons.
C. Radium has a higher atomic number.
D. Radium has more electrons in its outer energy level.

Answer 1

Radium is more reactive than calcium because it has more electrons in its outer energy level. Option D is the correct answer.

Step-by-step explanation:

Radium is more reactive than calcium because it has more electrons in its outer energy level. Option D is the correct answer. The reactivity of an element is determined by the number of valence electrons it has. Valence electrons are located in the outermost energy level of an atom and are involved in chemical reactions.

Radium, with an atomic number of 88, has two valence electrons in its outer energy level, while calcium, with an atomic number of 20, has two valence electrons as well. However, radium has more energy levels filled with electrons, which means it has more electrons overall.

Having more valence electrons and more filled energy levels gives radium a greater potential to react with other atoms and molecules, making it more reactive than calcium.