When drawing a bohr diagram for a hydrogen atom, if the element is in the 4th
excited state how many energy shells would you draw?

What happens when a rubber rod is rubbed with a piece of fur?

Directions: count the number of atoms. ar co2 na3po4 so3 nac2h3o2

Uranium has two naturally occurring isotopes. 238u has a natural abundance of 99.3% and 235u has an abundance of 0.7%. it is the rarer 235u that is needed for nuclear reactors. the isotopes are separated by forming uranium hexafluoride uf6, which is a gas, then allowing it to diffuse through a series of porous membranes. 235uf6 has a slightly larger rms speed than 238uf6 and diffuses slightly faster. many repetitions of this procedure gradually separate the two isotopes. what is the ratio of the rms speed of 235uf6 to that of 238uf6? express your answer to five significant figures.