Answer:
PROTON AND NEUTRON
Explanation:
- The mass of proton is :
A proton is one of the main particles that make up the atom . The other two particles are neutron and electron. Protons are found in the nucleus of the atom.This is a tiny , dense region at the centre of the atom. Protons have a positive charge of one (+1) and a mass of 1 atomic mass unit ( amu ) , which is about . Together with neutrons , they make up virtually all of the mass of an atom.
- The mass of neutron is also approximately:
but a little more than that .
Atoms of all elements - except Hydrogen , have neutrons in their nucleus . Unlike protons and electrons , these have no charge - they are electrically neutral . The mass of a neutron is slightly greater than the mass of a proton but not very significant