Which sequence of atomic numbers represents elements which have similar chemical properties? a
b
4, 20, 38,88
3, 12, 21, 40
9, 16, 33,50
19, 23, 30, 36
d

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 -

The answer is c.  h+  and oh−  react to form water (h2o). i just took the test and i got it right. hope this !