Through the process of active transport, materials move across a cell membrane: A.
between areas of equal concentration

B.
from an area of higher concentration to an area of lower concentration

C.
from an area of lower concentration to an area of higher concentration

D.
all of the above

This statement about matter and its behavior is best classified as a

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.

Ahelium balloon contains 16.9 l of helium at stp. how many atoms of helium are in the balloon