Your friend says," Chemical changes are caused by an input in energy. In physical changes, there is no transfer of energy." Is your friend correct? Why or Why not?

If a planet rotates 360 degrees during a 24 hour time period, what does that tell us about the planet? a. the middle of the planet is in darkness b. the seasons on the planet vary every day. c. the planet runs on a 12-hour time clock. d. the temperature on the planet varies daily.

If a reactant was removed, did the new equilibrium system shift to make more reactants or more products?

Which of these statements explains the difference between nuclear binding energy and the strong nuclear force ?