Mathematical model of hydrogen spectrum (1 Viewer)

[mozzie]

outline how Bohr’s postulates led to the development of a mathematical model to account for the existence of the hydrogen spectrum. (4)

I dont have enuf info nor depth of knowledge to ans a four mark qs on this ...can any one help

 

[ematouk]

answer

Here is an atom... for 4 marks, make sure you define the postulates, this is very important!

Bohr developed postulates inorder to explain the behaviour by which Rutherfords model could not explain such as the existance of set spectral lines rather then a continual spectrum of emission. Bohr's atom is essentially an uneasy mixture of both classical and quantum physics. Bohr's postulates include:
1. electrons circle the nucleus according to coulomb attraction in uniform circular motion.
2. electrons can only exist in definite stationary states around the nucleus.
3. when an electron orbits in a stationary state it does not radiate energy according to Maxwell's theory of electromagnetism
4. When an electron absorbs a certain frequency of energy it is able to jump up energy levels
5. When an electron drops energy levels it is able to radiate energy of a certain frequency.

It is these postulates which were assumed Balmer when he analysed the visible emission spectra of hydrogen being when an electron drops to the second energy level. Balmer derived an equation in term of an unknown value 'm' by which seemed to work when a number greater then 2 was substituted into it. Later other scientists began to analyse the spectra of non-visible spectrums such as Lymann and Pascen. These two scientists developed their own formulas independently to calculate the wavelength of emitted radiation. Later Rydburg combined the formula's to form another equation by which worked for the hydrogen atom for any series required.

(state equation because I couldn't be bothered typing it in)

This mathematical model based on the theory of Bohr's atom has developed the reason behind the emission spectrum aswell as provided mathematical evidence of the quantised energy levels of electron that exist within the atom.

 

[Jase]

Nice answer, for that I would give you 10 marks.

You see, this is the secret people... it's not about answering the question, because HSC physics questions never actaully make sense ever. It's about talking about as much as you can without getting too off track.

 

[nit]

Hmm, Bohr came after Balmer and Rydberg. I think that this is simply the dotpoint which asks how Bohr got to Rydbeg's equation.

So you'd talk about Balmer's equation, Rydberg's equation, and say that these were proven by Bohr's (dodgy) methods. If you really wanted to you could derive Rydberg's equation from Bohr's postulates, which would certainly indicate the understanding of the postulates and their scope.