An open flask sitting in a lab fridge looks empty, but we know that actually it is filled with a mixture of gases called air. if the flask volume is 3.50 l, and the air is at standard temperature and pressure, how many gaseous molecules does the flask contain?

Ascientist wants to know how individual lions within a pride interact with each other in their own environment. to do this, the scientist sedates and tags all of the lions within a pride. then, he places several remotely-controlled video cameras near the lions' den and performs an observational field study. he collects continuous video footage over the span of one year, analyzes the video, and then forms conclusions based on his observations.