Barium chloride solution is used to test for sulphates. Ionic equations must be balanced like ordinary equations and the overall electric charges on both sides must be the same. Calcium chloride and calcium hydrogen-carbonate have the same ionic equation with soap. Acids and alkalis all produce a salt and water. O 2 - H 2 O Zinc and acid.
More reactive elements displace less reactive ones.
Zinc displaces copper ions. Chlorine displaces bromine. An important lesson but your tutorial will not include averaging mass numbers if it is not listed in your syllabus . Simple numeric interactions are included to help you gain confidence. Atomic Particles Neutrons hold protons together in the nucleus.