The density of liquid mercury is 13.69 g/cm^3. how many atoms of mercury are in a 15.0 cm^3 sample? use "e" for "x10" and use sig figs.

Scientist wants to react a barium chloride salt with an acid. to speed up the reaction, the scientist crushes the barium chloride salt until it is a fine powder. this speeds up the reaction by a. increasing the ph of the salt. b. increasing the surface area of the salt. c. increasing the pressure of the salt. d. increasing the temperature of the salt. im thinking more a not 100% sure

Which part of earth’s surface receives the most direct rays from the sun? a) equator b) ocean c) poles d) mountains

Two people each hold the end of a rope and create waves by moving their arms up and down. this wave is best classified as a transverse wave because a) both the rope particles and the wave are moving in the same direction. b) the wave is moving up and down as the particles of the rope move horizontally. c) the wave is moving horizontally as the particles of the rope move up and down. eliminate d) the wave is moving in a parallel direction with the motion of the person's arms.