Understanding Reactivity in the Periodic Table

Which of the following statements is true?

Answer:

The correct statement is D: Mg is less reactive than Na because Mg has to lose one more electron than Na to complete its outermost shell.

Reactivity in the periodic table is determined by the number of electrons in an atom's outermost shell. Atoms tend to react in ways that allow them to achieve a stable electron configuration, typically by gaining, losing, or sharing electrons to complete their outermost shell.

Looking at the data provided, we see that sodium (Na) and magnesium (Mg) are both in column one and two respectively. Sodium has 11 electrons and magnesium has 12 electrons. Both of these atoms have one electron in their outermost shell.

When we compare sodium (Na) and magnesium (Mg) to calcium (Ca) and potassium (K), we see that calcium and potassium are in columns one and two respectively. Calcium has 20 electrons and potassium has 19 electrons. Both of these atoms have two electrons in their outermost shell.

Based on this information, we can determine that Mg is less reactive than Na because Mg has to lose one more electron than Na to complete its outermost shell. This extra electron makes magnesium less likely to undergo a chemical reaction compared to sodium, which only needs to lose one electron to achieve a stable configuration.