If a star is 75 light years away, how long is it before we see the light from that star on earth ?

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?

Amagnetic field applies forces on: a)static chargesb)moving chargesc)water flow

The photo shows sugar dissolved into a solution with excess sugar at the bottom of the jar this type of solution is classified as a. unsaturated b. compound c. saturated d. plasma