Identify the element that is correctly described based on the periodic table shown below.

• A. Element 4: A halogen that is a good electrical and thermal conductor.
• B. Element 1: An alkaline earth metal that is not found in nature in its pure state.
• C. Element 3: A transition metal that does not conduct electricity.
• D. Element 2: An alkali metal that has very low chemical reactivity.

Answer: (B)