Does adding acid make a solution more acidic or basic

Adding an acid increases the concentration of H3O+ ions in the solution. Adding a base decreases the concentration of H3O+ ions in the solution. An acid and a base are like chemical opposites. If a base is added to an acidic solution, the solution becomes less acidic and moves toward the middle of the pH scale.

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