is this the only photon energy that an electron in the n=6 energy level of a hydrogen atom could emit when it falls back to the n=2 energy level? explain

A2 kg ball travellng to the right with a speed of 4 m/s collidees with a 5 kg ball traveling to the left with a speed of 3 m/s. take right to be the positive direction. what is the total momentum of the two balls before they collide? what is the total momentum of the two balls after they collide?

Curious carl calculated the density of a cube to be 4.50 g/cm3. what is the density of the cube in g/l?

How many atoms of nitrogen are in the chemical formula ni(w on