Question

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? magnesium has a larger atomic number. phosphorus has a larger atomic mass. magnesium is in the same category as phosphorus. phosphorus has similar chemical properties as magnesium.

Explanation:

• Atomic number: Atomic number increases from left to right in a period. Magnesium (\(Mg\), atomic number \(12\)) is to the left of phosphorus (\(P\), atomic number \(15\)), so magnesium does not have a larger atomic number.
• Atomic mass: In the periodic table, as we move from left to right in a period (for main - group elements), the atomic mass generally increases. Magnesium has an atomic mass of approximately \(24.31\space g/mol\), and phosphorus has an atomic mass of approximately \(30.97\space g/mol\). So phosphorus has a larger atomic mass.
• Category: Magnesium is an alkaline - earth metal (Group 2), and phosphorus is a non - metal (Group 15). They are not in the same category.
• Chemical properties: Chemical properties are mainly determined by the number of valence electrons. Magnesium has \(2\) valence electrons, and phosphorus has \(5\) valence electrons. They do not have similar chemical properties.

Answer:

Phosphorus has a larger atomic mass.