Add electron dots and charges for the reaction of ca and o

The two atoms shown in the equation are CALCIUM and oxygen. 

You start off with a neutral calcium atom with a shell of two electrons, a shell of 8 around that, a shell of 8 around that, and a shell containing 2...with no charge. 
20 protons + 20 electrons. 

You also have an oxygen atom with a shell of 2, and a shell of 6...with no charge. 
8 protons + 8 electrons. 

Each ionizes to form a calcium ion with 2 electrons removed (from the outer shell), leaving a +2 charge (20 protons, 18 electrons)... 
and an oxygen ion with 2 electrons added (to the outer shell), leaving a -2 charge (8 protons, 10 electrons). 

Their electrostatic attraction causes them to come together to form an ionic compound of CaO in a crystal lattice.

Answer is: the equilibrium  shifts toward the reactants, to the left side of chemical reaction.it is because lead(ii) nitrate dissociates in water: pb(no₃)₂ → pb²⁺(aq) + 2no₃⁻(aq).according to lechatelier's principle, the position of equilibrium moves to counteract thechange (more lead cations, common ion), the position of equilibrium will move so that the concentration ofproducts decrease and concentration of reactants of chemical reaction increase.read more on -

H2so4 is the chemical compound of sulfuric acid.