Liquid nitrogen can change from a liquid to a gas without the help of a burner because the energy in the room is able to make it

Which two particles are found in the center of an atom

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.

Mary starts from her house, walks 80 meters south, and stops to chat with her aunt on the sidewalk. after chatting for a few minutes, she walks 125 meters to the west to meet a friend and then walks 45 meters north with her friend to a cafe for lunch. overall, she takes 10 minutes to do all this. what is mary’s average speed?