Question

Ultraviolet light emits a total of 2.5 × 10^–17 J of light at a wavelength of 9.8 × 10^–7 m. How many photons does this correspond to?

Answer 1

find how much energy one photon of this wavelength contains:

E=hc/lambda

then divide the total energy by the energy of the one photon.

Answer 2

6.626*10^-34*3.00*10^8/9.8*10^-7

Answer 3

looks good

Answer 4

2.5*10^-17/2.028*10^-19

Answer 5

yep

Answer 6

WELL I GOT 123 AND THE ANSWER I NEED 125 WHAT DID I DO WRONG

Answer 7

try not rounding up the speed of light

Answer 8

OK

Answer 9

CAN YOU HELP ME WITH THIS ONE

Which of the following statements is true?
a) Light with energy lower than the binding energy of an electron will result in an electron being ejected 0but having no kinetic energy.
b) Light with energy higher than the binding energy of an electron will result in multiple electrons being ejected from the surface.
c) Light with energy higher than the binding energy of an electron will result in an electron being ejected with the excess energy as kinetic energy.

Answer 10

well which one makes sense?

Answer 11

C

Answer 12

yep, thats right. If a photon of excess energy to be able to ionize an electron removes it, the rest will be translated into kinetic energy and the electron will go flying off

Answer 13

AND THIS ONE I NOT SURE I THINK ITS D
Which of the following is true regarding electromagnetic radiation?
a) As energy increases, wavelength and frequency increase.
b) As energy increases, wavelength and frequency decrease.
c) As energy increases, wavelength increases and frequency decreases.
d) As energy increases, wavelength decreases and frequency increases.

Answer 14

yep, you can verify by looking at plancks equation

E=hv=hc/lambda

Answer 15

THANK YOU SO MUCH

Answer 16

no problem dude