3 questions will chose brainlist

With i really need the correct answer!

Which type of bond is found between the atoms of a molecule? a. metallic b. delocalized electron c. covalent d. ionic

The solar panels used by mark function because of the photoelectric effect. light shines on the cells causing electrons to be ejected from the metal, which produces an electric current. at night on mars, no light will fall on the solar cells and no electric current will be generated. according to your notes, what type of light is typically needed to cause the photoelectric effect? a)visible b)ultraviolet c)infrared