Which movement of substances through a cell membrane against a concentration gradient requires energy?
question 16 options:

osmosis

diffusion

active transport

facilitated diffusion

The proton has a positive charge while the neutron has no charge they both make up the nucleus of the atom while the elections have a negative charge and surround the nucleus of the atom. the protons and electrons are used to calculate the atom's mass whereas the neutrons don't affect the mass

This is the most closely resembles the model.