What is the total number of protons in the nucleus of calcium -42?

The tilt of the earth's axis of rotation is responsible for the a) ocean's tides. b) size of the moon. c) brightness of stars. d) earth’s seasons.

#20 which type of bond is formed when bases pair in dna? ionic bond covalent bond coordinate bond hydrogen bond

Witch two conditions can limit the usefulness of the kinetic molecular theory in describing gas behavior?