Question

what do the purple - colored blocks indicate? halogens noble gases metalloids alkali metals

Explanation:

Metalloids are elements that have properties intermediate between metals and non - metals. In the periodic table, they are typically located along the staircase - like diagonal line separating metals from non - metals. The purple - colored elements (B, Si, Ge, As, Sb, Te, At) in the given periodic table are metalloids. Halogens are in Group 17, noble gases in Group 18, and alkali metals in Group 1.

Answer:

metalloids