The element phosphorus is located to the right of the element magnesium along the same period in the periodic table. Which best describes the relationship of the elements?

A. Magnesium has a larger atomic number

B. Phosphorus has a larger atomic mass

C. Magnesium is in the same category as phosphorus.

D. Phosphorus has similar chemical properties as magnesium.

Answer: Option (B) is the correct answer.

Explanation:

Atomic number is the number of protons present in an atom whereas atomic mass is the sum of total number of protons and total number of neutrons present in an atom.

Atomic number of magnesium is 12 and its atomic mass is 24.305 g/mol. On the other hand, atomic number of phosphorus is 15 and its atomic mass is 30.974 g/mol.

Also, it is known that atoms which belong to the same group show similar chemical properties because they have same number of valence electrons.

Thus, we can conclude that Phosphorus has a larger atomic mass best describes the relationship of the elements.

B - Phosphorus has a larger atomic mass.