### Units for DeBroglie

Posted:

**Tue Oct 01, 2019 11:23 am**Are the official units kg and meters? So if we were to be given a problem with km and g for instance, we would have to convert them?

Created by Dr. Laurence Lavelle

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

https://lavelle.chem.ucla.edu/forum/viewtopic.php?f=18&t=45791

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Posted: **Tue Oct 01, 2019 11:23 am**

Are the official units kg and meters? So if we were to be given a problem with km and g for instance, we would have to convert them?

Posted: **Tue Oct 01, 2019 1:17 pm**

The correct units for DeBroglie are kg and m, so as you suggested, we would need to change the units to kg and meters.

Posted: **Thu Oct 03, 2019 9:38 pm**

You use kg and m because those are the SI units used in the formula.

Posted: **Tue Oct 08, 2019 9:30 am**

Yes, the DeBroglie equation uses all SI units. Another way to look at the units involved, is to understand what units are appropriate for each variable involved (this can be found in the textbook or modules). For example, the units for Planck's constant are kg.m^2.s^-1 while the units for velocity is m.s^-1. It is helpful to remember that problems involving the DeBroglie Equation involve cancelling out units to get the proper units of the final answer, so memorizing what the proper units for each variable are, especially Planck's constant, can help you visualize when you need to convert units, and what final units you should end up with.

Posted: **Wed Oct 09, 2019 3:21 pm**

Yes! definitely would need to change from km*g to m*kg!! thanks to metric conversions the dimensional analysis is quite straightforward.