Answer:
9 protons 9 electrons and 10 neutron
Explanation:
The atomic number is the number of protons .In a neutral atom,the number of electrons equals the number of protons.Mass number is the sum of the protons and nuetrons of a particular isotope.If you have mass number and atomic number,subtract the atomic number from the mass number to get the number of nuetrons. Mass number- atomic number= number of nuetrons
