Which element has both metallic and nonmetallic properties?
(1) rb (3) si
(2) rn (4) sr

How do dying stars contribute to the formation of planets

In chemistry, the type of an atom (what element it is) is determined by: a) the number of protons it contains in its nucleus. b) the number of neutrons it contains in its nucleus. c) the number of protons it has in a cloud around the nucleus. d) the number of neutrons it has in a cloud around the nucleus. e) the number of electrons it exchanges with its neighbors.

Name 3 types of energy you see being used as you look around a classroom