The value of the atomic mass of an atom is a. the sum of the mass of the protons in the atom. b. the average mass of all the different ions of the atom. c. the average mass of all the different isomers of the atom. d. the average mass of all the different isotopes of the atom.

Compare and contrast physical changes with chemical changes.

Diffraction is when light is bent around obstructions. which of the these observation about clouds would indicate diffraction? a) after rain storms, you can sometimes see rainbows. b) clouds are white or gray and cannot be seen through. c) on a cloudy day, the temperature tends to be cooler than a sunny day. d) the edges of dark clouds appear lighter. this

The excretory system,need answers for all: )