When it is acted upon by an outside force
Board up your windows
Go to higher ground
Get food and water
Answer:
On the left side of calcium atom.
Explanation:
There are two dots are present on the left side of calcium atom which represents the unpaired electrons present in the outermost shell. This structure is presented by Lewis in order to show the number of unpaired electrons in the atom. if the calcium atom loses these two electron during a chemical reaction so the two dots disappear and the calcium atom is now stable.