Over time, one group of squirrels becomes separated from another group. due to erosion and the subsequent formation of a river, the squirrels are unable to cross. the geographic barrier prevents breeding between the two groups of squirrels. which term describes what the two groups of squirrels are not?

The two groups of squirrels are not the same species.

The term species implies towards the organisms, which possess the tendency to breed with each other. In the given case, the two groups of squirrels got separated due to geographical isolation, as the result both the groups were inhibited to have mated with each other. As a result, the two different species of squirrels got originated due to the phenomenon.  

heat a spark and oxygen

measuring light intensity

light meters can be used to measure light intensity. the meter is held at the soil surface and pointed in the direction of the maximum light intensity, and then the meter is read.

errors can be made when measuring light intensity by accidentally shading the light meter. the reliability of the results can be checked by taking many samples.