Through what voltage must an α-particle, with its charge of +2e, be accelerated so that it has just enough energy to reach a distance of 2.5×10−14 m from the surface of a gold nucleus? (Assume the gold nucleus remains stationary and can be treated as a point charge.

From 0 to 5 seconds john pushed a box 5 meters. from 5 to 10 seconds, paul pushed the same box another 5 meters. who did more work? a. john b. paul c. john and paul did the same amount of work.

Which compound is held together by the electrostatic force between two ions? a. co2 b. cci4 c. h2s d. mgf2

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.