1B. 7 Homework help

[905385366]

I am confused on where to start for homework problem 1B parts a - c. Am I supposed to convert the wavelength to energy? I guess I'm also confused about what the question is asking. Could someone help? Thanks?

[Anne Tsai 1F]

Part a is asking you to convert wavelength to energy. Part b is asking you to take that calculated energy (which is in joules per atom) and convert that into joules per gram, and part c is asking for joules per mole.

[Ruby Tang 2J]

For a) You can combine E=hv and c=λv to get E=hc/λ to find the amount of energy emitted. You know planck's constant (h), the speed of light (c), and wavelength (λ), so you just have to plug the numbers in to get the amount of energy emitted.
For b) You have to first find how many moles of Na are in 5.00 mg of Na, and then multiply by Avogadro's number to find the number of individual Na atoms there are. You can then multiply this by your answer to a) because you already solved for the amount of energy emitted by a single Na atom.
For c) This is basically b but with fewer steps. You are already given the amount of Na in moles, so you just multiply this by Avogadro's number and then multiply by your answer to a)

You should get 3.37*10^-19 J, 44.1 J, and 203 kJ for a, b, and c respectively.

[905385366]

thank you so much I figured it out