Ann is studying acid base neutralization reactions and mixes sodium hydroxide and hydrochloric acid. The reactants were clear, colorless solution and mixing them produces a clear, colorless final solution and the beaker becomes warm. She knows this reaction forms liquid water and an aqueous salt based on the neutralization rules as shown by the chemical equation. What physical evidence indicates that there has been a chemical reaction?

you need to take a look at the periodic system in order to sort these elements into pairs that would most likely exhibit similar chemical properties. first, you need to find elements that are found in the same group (groups are vertical in the periodic system), and then to see whether they have the same valence number. if they meet these criteria, they will have similar properties.

the first pair: ne (neon) and kr (krypton), are noble gases found in group 8

the second pair: li (lithium) and k (potassium), found in group 1

the third pair: s (sulfur) and te (tellurium), found in group 6

i just learnt this recently but i need to look through my notes again