The distance between a proton and an electron is cut in half. how does the force of attraction change? a) the force becomes twice as much. b) the force becomes one-half as much. c) the force becomes four times as much. d) the force becomes one-quarter as much.

Which statement describes the appearance of a temperature-vs.-time graph? a horizontal line shows that the temperature increases at a constant rate over time. a vertical line shows that the temperature decreases at a constant rate over time. horizontal lines where the temperature is constant during phase changes connect upward-sloping lines where the temperature increases. horizontal lines where the temperature increases are connected by upward-sloping lines where the temperature is constant for each phase.

Solar energy is energy from the sun that is converted into thermal or energy. a. nuclear b. mechanical c. electrical d. chemical

Avariable that is not being directly tested during an experiment should be