Question

what do the red - colored blocks indicate? alkali metals noble gases alkaline earth metals non - metals

Explanation:

Alkali metals are in Group 1, alkaline - earth metals in Group 2. Noble gases are in Group 18 and non - metals are elements that are not metals. The red - colored blocks in the periodic table shown include elements like hydrogen, carbon, nitrogen, oxygen etc. which are non - metals.

Answer:

non - metals