Question

calcium is shiny, malleable, fairly reactive, conducts electricity well, and has an oxidation number of +2. based on its placement on the periodic table, which element will have very similar properties to calcium but will have a much larger atomic radius and be more reactive? a) ba b) ti c) k d) mg

Explanation:

1. First, recall the periodic table trends: Elements in the same group (vertical column) have similar properties. Calcium (Ca) is in Group 2 (alkaline earth metals).
2. Analyze each option:

• Option A: Barium (Ba) is also in Group 2. As we go down a group, atomic radius increases (more electron shells) and reactivity (for Group 2 metals) increases because it's easier to lose electrons.
• Option B: Titanium (Ti) is a transition metal, not in Group 2, so properties differ.
• Option C: Potassium (K) is in Group 1 (alkali metals), different group, so properties like oxidation number (+1 vs +2 for Ca) differ.
• Option D: Magnesium (Mg) is in Group 2, but above Ca. Going up a group, atomic radius decreases and reactivity is lower than Ca (and Ba, which is below Ca). So Ba is below Ca in Group 2, has larger atomic radius and is more reactive.

Answer:

A. Ba