True or False? The convection currents in the mantle
are mainly caused by heat coming
from the core.

true

Explanation:

convection currents occur when a heated fluid expands, becoming less dense, and rises. The fluid then cools and contracts, becoming more dense, and sinks

heat go up, cold go down. they cycle.

False

Explanation:

correct answer is option a.

tropopause, stratopause and mesopause have all in common aspect that is point of maximum temperature in its layer of the atmosphere. all layers of atmosphere observe abrupt change in temperature. tropopause is the boundary between troposphere and stratosphere. stratopause is the boundary between stratosphere and mesosphere. mesopause is the boundary between mesosphere and thermosphere. these all boundaries are ranges between altitude of 0 to 80 km.

meteorologists would compare a new weather map with one 24 h old to see how fast a front is moving.