Why do the 3s, 3p, and 3d orbitals have the same energy in a hydrogen atom but different energies in a many-electron atom?

John throws .4 kg ball with velocity of 18 m/s. hits .2 kg bottle and bottle flies 25 m/s. how fast is ball traveling after hitting the bottle?

Kate is working on a project in her tech education class. she plans to assemble a fan motor. which form of energy does the motor convert most of its electric energy into? a. light energy b. motion energy c. sound energy d. thermal energy

What occurs during a combustion reaction