What happens in a global convection cell?
a. cool air moves upward in the center; warm air moves downward at
the edge.
o
b. warm air and cool air move in circles, causing hurricanes and
tornadoes.
o
c. cool air and warm air repeatedly collide, pushing air up and
causing storms.
o
d. warm air moves upward in the center, cool air moves downward at
the edge

rocks and weathering-matching

the relative atomic mass of an element is the mass of one atom of that element, relative to 1/12th of the mass of a  1212c atom. to convert to an absolute mass in kg, it is necessary to multiply by  1.661×10−271.661×10−27.

the relative atomic mass is roughly equal to the number of neutrons, plus the number of protons, in the nucleus of the atom.

for elements with more than one stable isotope (different types of nucleus with different numbers of neutrons but the same number of protons), the quoted mass is usually the average mass, weighted by the relative abundance of the different isotopes.