3. Compared to the entire atom, the nucleus of the
atom is
A.
smaller and contains most of the atom's mass
B.
smaller and contains little of the atom's mass
C.
larger and contains most of the atom's mass
D. larger and contains little of the atom's mass

15. which of the following is not human-caused groundwater pollution? a. water in an aquifer dissolves elements such as arsenic and mercury from surrounding rock. b. water in an aquifer is contaminated by leachate that seeps into the ground from a landfill. c. water in an aquifer becomes polluted with chemicals used in hydraulic fracturing, or fracking. d. water in an aquifer absorbs harmful bacteria from the drainage field of a septic tank.

Rays from the sun are not considered matter true or false

Is this correct if not can u correct me