A box is 0.6 meters long and 0.2 meters wide and 0.5 meters tall. If the radius of a ping pong ball is .019 meters, about how many ping pong balls will it take to fill up the box? The volume of a sphere is 4pr3/3.

Hydrogen atoms are excited by a laser to the =4n=4 state and then allowed to emit. what is the maximum number of distinct emission spectral lines (lines of different wavelengths) that can be observed from this system? 8 6 2 7 4 5 1 3 calculate the wavelength of the 4⟶14⟶1 transition. =λ=