A dot and cross diagram for sodium chloride suggests that it is made up of pairs of sodium and chloride ions. It is not. A 3D construction model shows how the ions are arranged in a lattice structure.

The atoms in the reactants are: 1 calcium atom, 2 chlorine atoms, 2 sodium atoms, 2 hydrogen atoms, 2 carbon atoms, and 6 oxygen atoms The atoms in the products are: 1 calcium atom, 2 chlorine atoms, ...

For example, the atomic number of sodium is 11. Every sodium atom has 11 protons and 11 electrons. It has 11 positive charges and 11 negative charges. The mass number of an atom is its total ...

Since this atom has a total of eight electrons ... After the second level has 8 electrons, the next electron goes into the third level. 3rd Period: Sodium to argon—Electrons go into the third energy ...