A student has two solid blocks that have different masses. The student knows that each block is composed of a pure substance, but she wants to know if the blocks are composed of the same pure substance. Which of these would best show that the blocks are composed of different substances? A. Both blocks can be scratched by a piece of glass. B. Both blocks sink when placed in water. C. One block conducts electricity and the other does not. D. One block has a greater volume than the other block.

Imagine that a new planet is discovered with two moons of equal mass: moon a and moon b. the mass of the new planet is greater than the combined mass of its moons. moon a is farther away from the new planet than moon b. what is the planet's gravitational pull on moon a compared to the planet's gravitational pull on moon b? the planet's gravity repels moon a with a greater force than it repels moon b, which is why moon a is farther away. the gravitational pull on moon b is greater than on moon a because moon b is closer to the new planet than moon a. the gravitational pull on moon b is greater than on moon a because moon b is farther away from the new planet than moon a. the gravitational pull on moon a is the same as the gravitational pull on moon b because distance does not affect the planet's gravity.