# Bohr Model / Energy question

1. Jun 1, 2006

### nophun6

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 dont understand what they want for an answer.

Thanks in advance for the help!!

2. Jun 1, 2006

### Andrew Mason

Q1 What is the energy at $n = \infty$? What is the energy at n =1 ? What is the difference?

Q2 What is the gravitational potential energy of the planet in orbit and what is its escape energy (ie. energy needed to make $r = \infty$)? It is a similar concept to the Bohr model of the atom except that the energy levels permited for a planet in orbit are much finer than those for an electron obiting a proton. In both cases, as the forces are attractive, energy must be added to remove the obiting body.

AM