Astudent reported that a limp stalk of celery became crisp when placed in ice water this is an example of a/an

The answer is an observation

the potatoes have high sugar concentrations and although these potatoes were different we could seethe effects that their sugar concentrations had in different environments. for example, the potatoes in sample a, were placed in pure water. this created a hypertonic environment and caused the potatoes to draw in water from its surroundings. we saw the opposite happen with the potatoes in sample b when placed in the sodium chloride solution. the potatoes in this case were in a hypotonic solution and therefore lost water to their surroundings.

"it built up in the atmosphere"

i think thats it, idk, i tried looking for this exact q& a for grad. and idk if i got this question right or sorry if im wrong