How often a person exercises. the number of times a person engages in moderate to vigorous activity is called?

The answer is "Frequency"

Explanation:

Frequency has to do with the rate way which something is done at a particular given period of time. It can also be defined as the number of times a repeating event occurs.

the plates spread at mid-ocean ridges (they are divergent plate boundaries) which allows magma to rise through the weakness between the plates. the magma then emerges as lava from the boundary and cools, creating a new crust.