Tricky question (1 Viewer)

[acmilan]

Last year in the CSSA trial a hell of a lot of people were tricked in one of the option questions. The question was to determine the ionisation energy of the hydrogen atom. I posted this just to make sure that people know how to do this in case they get it in a trial or hsc since the method is different to determining binding energy. Feel free to have a try of how to do it before i show how to do it

 

[mojako]

Ionisation energy is the energy required to remove an electron from the atom (the outermost electron to be exact).
Binding energy is the energy required to break all the bonds between nucleons (nucleons are protons and neutrons) in the atom.
Of course they are different.
BUT: I haven't seen any reference to ionisation energy in my textbook even though I've read all core modules plus the From Quanta to Quarks section. And the term is not in the glossary either. And I don't remember reading or being told about it in year 11 Physics.
EDIT: There's a section related to ionisation which is on the spectral lines.
Depends on what the question tells you, you can find the difference between two energy states (in the 2 shells) [EDIT: one shell is when n = 1 and the other is with n = infinity, the formula for finding energy at a particular shell is En = E1 / n^2] if they tell you that information [EDIT: if they give you the value for either E1 or E2 or any other En], or you can use "E = h f" if they tell you what light frequency is needed to excite the electron. [EDIT: or you can use the formula as explained in the next post if they don't give you anything]

 

[acmilan]

Basically you take n(f) to be infinity and n(i) to be 1, use the formula and you will get a wavelength of -1/1.097x10^7. Then use E=hf to find E. E will be negative meaning energy must be applied to remove the electron