# E=hf...whats the units?

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Thread starter 1 year ago
#1
Energy is in eV right?
0
1 year ago
#2
E = hf
E = Energy of the photon in Joules (J)
h = Planck's Constant (6.63 x 10^-34 J s)
f = Frequency (Hz)
1
1 year ago
#3
(Original post by vix.xvi)
Energy is in eV right?
It can be eV or J.

Sometimes, eV is preferred because joule is a large unit in nano-scale or quantum mechanics.

Planck constant be written in terms of eV⋅s or J⋅s.
h = 6.626 × 10‒34 J⋅s = 4.136 × 10‒15 eV⋅s
1
1 year ago
#4
(Original post by vix.xvi)
Energy is in eV right?
J, kWh, eV, calorie.
Ultimitly all define the same thing, just to different scales
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Thread starter 1 year ago
#5
(Original post by mnot)
J, kWh, eV, calorie.
Ultimitly all define the same thing, just to different scales
thanks!
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Thread starter 1 year ago
#6
(Original post by mnot)
J, kWh, eV, calorie.
Ultimitly all define the same thing, just to different scales
wait is there a way to convert from eV to J?
0
1 year ago
#7
(Original post by vix.xvi)
wait is there a way to convert from eV to J?
Yes, 1 eV = 1.6 x 10^-19 J
1
1 year ago
#8
(Original post by vix.xvi)
wait is there a way to convert from eV to J?
Yes 1 J = 6.242x10^18 eV
0
1 year ago
#9
(Original post by vix.xvi)
wait is there a way to convert from eV to J?
You remember the equation E = QV?
Well an electronvolt is the E when the charge is equal to an electron's charge and the potential difference is 1V. The charge of an electron is -1.6*10-19 C.
1
Thread starter 1 year ago
#10
(Original post by Sinnoh)
You remember the equation E = QV?
Well an electronvolt is the E when the charge is equal to an electron's charge and the potential difference is 1V. The charge of an electron is -1.6*10-19 C.
(Original post by mnot)
Yes 1 J = 6.242x10^18 eV
(Original post by SAARH.A5)
Yes, 1 eV = 1.6 x 10^-19 J
Thanks so much
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