## HW 1.25b

$c=\lambda v$

Alex McCorriston Dis 3A
Posts: 18
Joined: Fri Sep 29, 2017 7:04 am

### HW 1.25b

Question:

1.25 Sodium vapor lamps, used for public lighting, emit yellow light of wavelength 589 nm. How much energy is emitted by
(b) 5.00 mg of sodium atoms emitting light at this wavelength;

Is energy always measured in Joules per atom? You have to use dimensional analysis in this problem and I got stuck after converting from grams to atoms.

Thank you!

Ivy Lu 1C
Posts: 54
Joined: Thu Jul 27, 2017 3:00 am

### Re: HW 1.25b

First, you would convert the 5.00 mg to atoms. Once you have that, you just multiply by the Joules per atoms that you got from part a. The atoms of sodium should cancel leaving you with just Joules.

Miguel Velasco 2J
Posts: 40
Joined: Fri Sep 29, 2017 7:07 am
Been upvoted: 1 time

### Re: HW 1.25b

Use Avogadro's number to turn grams to atoms!