# Value of inifinity?

1. Dec 19, 2007

### alexlee33

[SOLVED] Value of inifinity?

Edit: typo in title (infinity); sorry

1. The problem statement, all variables and given/known data

What is the shortest wavelength of light emitted by an electron in the Brackett series of spectra lines of the hydrogen atom?

2. Relevant equations

1 / (wavelength) = RH ( (1/nu^2) - (1/nl^2) )

3. The attempt at a solution

1 / (wavelength) = 1.1 x 10^7 ( (1/4^2) - (1/(infinity???)^2) )

I am told the correct answer is 1.45 x 10^-6, but I cannot find it on my calculator because I am not sure what to put in the place of infinity.

Thanks!!

Last edited: Dec 19, 2007
2. Dec 19, 2007

### Dick

One over a number infinitely close to infinity is infinitely close to zero. Just put in zero for the second term.

3. Dec 19, 2007

### Shooting Star

The value of 1/x tends to zero as x tends to infinity.So, just put zero in place of 1/n1^2.

4. Dec 20, 2007

### Shooting Star

(Sorry Dick, it seems we were typing at almost the same time.)

5. Dec 20, 2007

### alexlee33

Thanks guys! :)