Answer:
Sodium is a member of the <u>Alkali Metals family</u> and Calcium is part of the <u>Alkaline Earth Metals family</u>.
Alkali Metals characteristics: Silvery solid, very soft, low density, low melting point, extremely reactive especially in water, has 1 valence electron, reactivity increases as you go down the family.
Alkaline Earth Metals characteristics: contain 2 valence electrons, harder and denser than Alkali Metals, never found free in nature, and highly reactive.
Explanation:
Alkali Metals: Keep in mind Hydrogen is not part of the family, its just there in the same column because of the number of valence electrons in has.