If an object has luster, is brittle, and is a semi-conductor, what category would best describe it? A. Metal

B. Non-metal

C. Metalloids

D. Isotopes

What produces light and all other electromagnetic waves? a) the photoelectric phenomena b) heated metals c) charged particles d) radioactive samples (pls explain if you can : )

Asystematic approach to problem solving is called a (an)

Think you could get me the answers ?