Particles of sand or dust rubbing across the surface of rocks is called

Which statement justifies that phosphine (ph3) is a polar molecule?

What are scientists who study fossils called? ( a ) astronomers. ( b ) biologists. ( c ) geologists. ( d ) paleontologists.

Select all that apply. using a value of ksp = 1.8 x 10-2 for the reaction pbcl2 (s) pb+2(aq) + 2cl -(aq). the concentration of the products yield a ksp of 2.1 x 10-2: