What does an unconformity in a sequence of rock layers reveal about geologic history? a. An organism went extinct during that time

b. a layer of rock might have eroded causing a gap in the record

c. the layers of rock cover hundreds of square miles

d. the new rock layers have been deposited very quickly

Can you use radiation to generate electricity

An incident ray through the focal point of a spherical mirror will: reflect through the center of curvature. reflect back through the focal point. reflect parallel to the principle axis. reflect the same direction as the incident ray.

Aprotein molecule in an electrophoresis gel has a negative charge. the exact charge depends on the ph of the solution, but 30 excess electrons is typical. what is the magnitude of the electric force on a protein with this charge in a 1600n/c electric field? write in two significant numbers, and also in newton