Question

which determines the reactivity of an alkali metal?
○ its boiling and melting points
○ the shininess of its surface
○ the number of protons it has
○ its ability to lose electrons

Explanation:

Alkali metals are in Group 1 of the periodic table and have one valence electron. Reactivity in chemical reactions (especially for metals) is related to how easily they can lose electrons to form positive ions. Boiling/melting points relate to physical state changes, shininess is a physical property, and the number of protons (atomic number) defines the element but not directly reactivity. The ability to lose electrons (ionization tendency) determines how reactive an alkali metal is as they react by losing their single valence electron.

Answer:

D. its ability to lose electrons