Which two substances are covalent compounds? A. C6H12O6(s) and KI(s)
B. C6H1206(s) and HCl(g)
C. KI(S) and NaCl(s)
D. NaCl(s) and HCl(g)

How do the energy differences between the higher energy levels of an atom compare with the energy difference between the lower energy level of the atom

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.

The number of neutrons is equal to the atomic number minus the atomic mass. a. true b. false