Which electron in an atom (Z=17) is the most shielded from nuclear charge?
A. an electron in the 2s B. an electron in the 3p
C. an electron in the 3d D. an electron in the 1s

Which of these best describes the scientific process

Which sentence best describes the formation of igneous rock? a- lava on the surface dries up and makes arock b_melted rocks cools and forms crystals c_rocks under tremendous heat and pressure d_magma is melted rock underground

The tilt of the earth's axis of rotation is responsible for the a) ocean's tides. b) size of the moon. c) brightness of stars. d) earth’s seasons.