Acatalyst is added to a system at equilibrium. if the temperature remains constant, the activation energy of the forward reaction
(1) decreases(2) increases(3) remains the same

Idon't know hope someone you

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 -

Zinc contains about 30 protons 

Answer/// he concludes that the atom particles can be broken due to the paddle wheel being moved by particles coming out of the metal;