Help me please! Why was the microscope and its improvement an important part of the development of the cell theory?

How are elements arranged in a periodic table

Clyde and marilyn are riding a roller coaster. during which section(s) of the track is their potential energy converted to kinetic energy? a. from point b to point c only b. from point b to point d only c. from point a to point b only d. from point a to point b and from point c to point d

Elements in group 2 are all called alkaline earth metals. what is most similar about the alkaline earth metals?