Ques: With a higher concentration of hydrogen ions, a solution is more acidic but has a lower pH. If Milo increases the concentration of hydrogen ions in his swimming pool, what happens to the acidity of his pool increases or decreases?
Ans: increases

Ques: To reduce friction, oil is added to the engine. When two pieces of metal are rubbing together and oil is added between them the friction decreases or increases?
Ans: decreases

Ques: Water becomes more dense when it is colder and when it has more salt. What happens to water when it absorbs less salt lower density or Higher Density?
Ans: lower density

Ques: The more tightly packed the particles inside the material are, the more dense we say they are. Sasha is throwing bottles into the lake. Some bottles are filled with sand, and some only have a tiny bit of sand in them. The bottles filled with sand will sink first because they are less dense or more dense?
Ans:
more dense