The top layer of skin is the epidermis
For the first one, electrons travel around the nucleus in fixed energy levels with varying energies.
Second one, protons, neutrons, and electrons have a mass, but electrons have far less mass
Third one, cations and protons
Fourth, not sure.
It is because liquids can move through it.
The atp is shuttled to the mitochondria because the mitochondria can use the stored energy and make it into used energy
The gas that the planet produces
