Which term describes a pure substance that is made up of only one type of atom? matter
rock
compound
element

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

It's either -limiting factors or -scarce resources but i'd go with my first answer since the food and water are abundant they really aren't scarce