Answer:
Ca generally loses two electrons from its outer shell to form a Ca2+ ion.
These are formed when, after formation of the first atom, the pi-orbitals of Sulfur and Oxygen align and share another pair of electrons. This occurs between sulfur and both of the oxygen atoms, with each oxygen atom forming one pi-bond.
The atomic number of an atom is determined by the number of protons it has..
It is also the whole number shown on the periodic table
