Calcium has an atomic number of 20 and an atomic mass (weight) of 40. Therefore, we know that calcium has
20 protons
40 protons
40 electrons
20 neutrons
20 electrons
select all that apply
![Calcium has an atomic number of 20 and an atomic mass weight of 40 Therefore we know that calcium has 20 protons 40 protons 40 electrons 20 neutrons 20 electron class=](https://us-static.z-dn.net/files/dee/487efcecb9dabed03fa025fe49749359.png)