Question

elements in the alkali metals group all have 1 valence electron; this means they all
only form covalent bonds
have similar chemical and physical properties to each other
are stable and not reactive
have chemical properties that are different from each other

Explanation:

• Alkali metals (Group 1 elements) have 1 valence electron. Valence electrons play a crucial role in determining an element's chemical properties. Since they have the same number of valence electrons, they tend to react in similar ways (chemical properties). Also, they have some similar physical properties (e.g., softness, low density compared to other metals).
• They do not only form covalent bonds. They usually form ionic bonds by losing their single valence electron.
• They are not stable. They are highly reactive as they readily lose that one valence electron to achieve a stable electron configuration.
• Their chemical properties are similar, not different, because of the same number of valence electrons.

Answer:

have similar chemical and physical properties to each other