### When to use DeBrogile's Equation

Posted:

**Sun Oct 20, 2019 6:26 pm**How do we know when to use DeBrogile's equation? Do we only use it for electrons, since they have a mass, while photons do not?

Created by Dr. Laurence Lavelle

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

https://lavelle.chem.ucla.edu/forum/viewtopic.php?f=18&t=48275

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Posted: **Sun Oct 20, 2019 6:26 pm**

How do we know when to use DeBrogile's equation? Do we only use it for electrons, since they have a mass, while photons do not?

Posted: **Sun Oct 20, 2019 6:37 pm**

DeBroglie's Equation is used for things or particles that have mass and that behave like a wave.

Posted: **Sun Oct 20, 2019 7:00 pm**

For DeBrogile's and other like equations, you have to read the question and what it ask for, and sometimes you might have to combine two equations to get the desired value that you look for. But for DeBrogile's equation you use it for anything that has mass and behaves like a wave.

Posted: **Sun Oct 20, 2019 7:04 pm**

The equation is only practically used for objects that have an observable wavelength. Since objects like cars have a velocity and mass, and therefore momentum, they have a wavelength when plugged into the equation. But, since the mass of the car is too great, the momentum is too high and the wavelength is not observable. The wavelength needs to be within the angstrom (1x10^-10m) range to be observable from what Lavelle said.

Posted: **Sun Oct 20, 2019 7:05 pm**

Also protons do have a mass, so they could be theoretically applied to the equation.