Calcium has 20 protons and 20 electrons. It can exist as an atom or an ion, depending on the specific circumstances. When it loses two electrons, it becomes a positively charged ion, Ca2+.
Calcium (Ca) is an element with an atomic number of 20, which means it has 20 protons in its nucleus. Since a neutral atom has the same number of protons and electrons, calcium also has 20 electrons surrounding its nucleus. Therefore, calcium is an atom, not an ion.
