### 7th edition 1B.5

Posted:

**Sat Oct 13, 2018 11:12 pm**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?

Created by Dr. Laurence Lavelle

https://lavelle.chem.ucla.edu/forum/

https://lavelle.chem.ucla.edu/forum/viewtopic.php?f=15&t=33772

Page **1** of **1**

Posted: **Sat Oct 13, 2018 11:12 pm**

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?

Posted: **Sun Oct 14, 2018 12:05 am**

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.

Posted: **Tue Oct 16, 2018 12:29 pm**

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.

Posted: **Tue Oct 16, 2018 1:11 pm**

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!

Posted: **Tue Oct 15, 2019 4:31 pm**

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!

Posted: **Sun Oct 20, 2019 6:49 pm**

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