Which nuclear emission has no charge and no mass?
(1) alpha particle (3) gamma ray
(2) beta particle (4) positron

Which of the following did jj thompson discover about atoms? a)an atom has an internal structure. b) atoms are tiny indivisible particles. c)electrons orbit the nucleus of an atom. d) the nucleus of an atom contains protons and neutrons.

Which of the following words describe the reality that the universe looks the same from various perspective

Who examines and coordinates the cleanup of polluted sites?