Please help (Science question)

Dr. arenas is a scientist who has been trying to determine if increasing pressure will increase the sound that occurs when two chemicals explode. it measures the volume of the sound that occurs at the minimum pressure at which the explosion will occur. it then increases the pressure and measures the volume of the explosions that occur. what kind of investigation is the scientist conducting?

Biology students used raw eggs in an experiment on tonicity and osmosis. the students put their eggs into vinegar to remove the shells. the vinegar was used to remove the shell from the raw egg. what other effect(s) did the vinegar have on the egg?

What is a quantitative observation? a. an observation that proves the hypothesis is wrong. b. an observation about the number or amount of something. c. an observation about the color, shape, size, or condition of something. d. an observation in which the appearance of something is described using descriptive language.