Posted by Tracey on Tuesday, May 26, 2009 at 3:53pm.
Q: From the Bohr model of the Hydrogen atom, calculate the minimum amount of energy (in eV) an electron in the lowest orbital would need to free it from its proton (i.e., to ionize the atom).
A: would I use the equation: En =  13.6 / (n^2) ?
If so, an an electron in its ground state would be n= 1
So the answer would be 13.6 eV ?
Q2: If you consider the Bohr model of the atom, where the proton and electron act as two bodies of mass, and the electron escapes from the pull of the proton with the energy found in part A, how is this similar to the energy needed for one body of mass, like a planet, to escape the gravitational force of another planet?
A2: I understand that in order for a planet to escape the gravitational force of another planet energy must be exerted, just as with the proton and electron, but I don't understand what they want for an answer.

Physics  drwls, Tuesday, May 26, 2009 at 5:26pm
Q1. The answer is +13.6 eV A removed electron at infinite distance is defineed to have zero energy.
Q2. Both are analogous inversesquarelaw situations. The ionization energy needed to remove an electron is similar to the "escape velocity" kinetic energy needed to leave the surface of a planet, and go to infinite distance (not an orbit). Going into orbit requires less energy than escap9ing the planet.