Which feature of a balanced chemical equation demonstrates the law of conservation of mass?
O A. It has the same types of atoms on both sides of the reaction
arrow.
O B. It shows the reactants of a chemical reaction to the left of the
reaction arrow.
O C. It has coefficients to show how much of each substance a
chemical reaction uses.
Thing
D. It shows the products of a chemical reaction to the right of the
reaction arrow.

Which statement correctly describes the relationship between frequency and wavelength?

As you are trying to move a heavy box of mass m, you realize that it is too heavy for you to lift by yourself. there is no one around to , so you attach an ideal pulley to the box and a massless rope to the ceiling, which you wrap around the pulley. you pull up on the rope to lift the box. use g for the magnitude of the acceleration due to gravity and neglect friction forces. once you have pulled hard enough to start the box moving upward, what is the magnitude f of the upward force you must apply to the rope to start raising the box with constant velocity? express the magnitude of the force in terms of m, the mass of the box.

Exercise 2. find the wavelength of a photon emitted when an electron jumps from the n = 3 energy level down to the n = 2 energy level. where is this photon in the electromagnetic spectrum?