Question

question 6 of 10
which of the following is a characteristic property of the alkaline earth metals?
a. they all have 3 valence electrons.
b. they are more reactive than alkali metals.
c. they are all radioactive.
d. they are harder than alkali metals.

Explanation:

• Option A: Alkaline earth metals (Group 2 elements) have 2 valence electrons, not 3.
• Option B: Alkali metals (Group 1 elements) are more reactive than alkaline earth metals.
• Option C: Not all alkaline earth metals are radioactive. For example, calcium (\(Ca\)) is not radioactive.
• Option D: Alkaline earth metals have smaller atomic radii and higher melting points compared to alkali metals, which makes them harder.

Answer:

D. They are harder than alkali metals.