All of the above reactions are chemical reactions that involve different chemical compounds reacting with each other to form new compounds.

NaCl + AgNO3 -> AgCl + NaNO3 (silver chloride is formed)NaBr + AgNO3 -> AgBr + NaNO3 (silver bromide is formed)NaI + AgNO3 -> AgI + NaNO3 (silver iodide is formed)Zn + HCl -> ZnCl2 + H2 (zinc chloride and hydrogen gas are formed)CuO + HCl -> CuCl2 + H2O (copper(II) chloride and water are formed)NaOH + HCl -> NaCl + H2O (sodium chloride and water are formed)CaCO3 + HCl -> CaCl2 + CO2 + H2O (calcium chloride, carbon dioxide, and water are formed)