Use the periodic table to answer the question.

Question

Which Statement about magnesium [Mg] and calcium [Ca] is correct?

They are both classified as noble gases.
They both have the same number of valence electrons.
They both have the same number of electron shells.

Answer 1

To determine the correct statement about magnesium (Mg) and calcium (Ca), let's analyze their properties based on the periodic table:

1. Noble Gases: Both magnesium and calcium are not classified as noble gases. Noble gases are found in Group 18 of the periodic table (e.g., helium, neon, argon, etc.), whereas magnesium is in Group 2 and calcium is also in Group 2.

2. Same Number of Valence Electrons: Both magnesium and calcium have the same number of valence electrons. They are both in Group 2, which means they have 2 valence electrons.

3. Same Number of Electron Shells: Magnesium (atomic number 12) has 3 electron shells, while calcium (atomic number 20) has 4 electron shells. Therefore, they do not have the same number of electron shells.

Based on this analysis, the correct statement is:

They both have the same number of valence electrons.