The best answer would be C.
The mass of an element depends on the number of particles found in the nucleus of the atom. Atomic mass can be computed by adding the number of protons and the number of neutrons. Protons and neutrons are found in the nucleus of an atom. So the answer must be letter C.
To separate a mixture of salt and water, you can try first by using filter paper hen with the extra water part set it out to the window so that the salt water evaporates and only the salt is remaining.
If you count the number of seconds between the flash of lightning and the sound of thunder, and then divide by 5, you'll get the distance in miles to the lightning: 5 seconds = 1 mile, 15 seconds = 3 miles, 0 seconds = very close. Keep in mind that you should be in a safe place while counting.
When a red giant has insufficient mass it pretty much sheds its outer layer to leave the center core know as the white dwarf
