## 7th edition 1B.5

$E=hv$

Alyssa Bryan 3F
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Joined: Fri Sep 28, 2018 12:26 am
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### 7th edition 1B.5

In this question, the energy is given in keV and we are given a conversion from eV to joules. What is keV and what is the difference between this unit of measurement and joules?

Lily Smith 4C
Posts: 16
Joined: Fri Sep 28, 2018 12:27 am

### Re: 7th edition 1B.5

KeV is Kiloelectron Volts so 10 to the third of standardized. Change this to regular electron Volts (eV) and you should be able to do your conversion.

Grace Kim 1J
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### Re: 7th edition 1B.5

Kiloelectron volt (keV) is one thousand electron volts. To convert keV to joules, you just need to remember the formula that 1 J= 1.6022x 10^-19 keV. Joules and eV is connected in the sense that the potential difference of 1 volt causes an electron to gain an amount of energy.

Kelsey Warren 1I
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Joined: Fri Sep 28, 2018 12:15 am

### Re: 7th edition 1B.5

I agree with everything stated above I just wanted to clarify that 1 eV=1.6x10^-19 J, not the other way around. Hope this helps!

vanessas0123
Posts: 47
Joined: Wed Sep 11, 2019 12:17 am

### Re: 7th edition 1B.5

1eV (electronvolt) = 1.6022x10^-19J (joules), so 1keV (kilo-electronvolt) = 1.6022x10^-16J. The energy in the formula E=hv is in joules, so you need to convert first!

NRodgers_1C
Posts: 53
Joined: Thu Jul 25, 2019 12:15 am

### Re: 7th edition 1B.5

Does anyone know if this unit conversion is given on the formula sheet or must be memorized?