- Physical Sciences
water droplets that combine with one another, grow too heavy to stay in the air, and fall to the ground as snow, rain or hail.
no atoms are gained or lost during a chemical reactions.
Niels Bohr put forward the theory that electrons move in certain orbits about the nucleus.
the sum of the atomic masses of the atoms in a molecule.
horizontal rows of elements in the periodic table that are arranged according to their atomic...