If the relative mass of a proton is 1, what is the relative mass of a neutron?
You said: 1
What is the mass number of an atom?
You said: The number of neutrons and protons in the atom (because the mass of electrons is too small compared to the mass of neutrons and protons)
What is the atomic number of an atom?
You said: The number of protons it contains
Isotopes of an element have:
You said: The same number of protons (because Isotopes have different numbers…