The two electrons in a helium atom occupy and have electron spins.
orbital(s)

a the same, opposite
b different; the same
c the same, the same
d different; different

What must happen before a body cell can begin mitotic cell division

Skills of homo sapiens were found an excavation. the skulls were preserved because the bodies were frozen. so, these fossils are (blank) fossils.the image shows the evolution of skulls beginning 2 to 3 million years ago. based on the image, modern human skulls(blank) ape skulls.

How many moles of lead are in 1.50 x 10^12 atoms of lead? could you explain the answer as well and not just give it to me i am refreshing for finals and i need to know how to do it