## 1.39

$\lambda=\frac{h}{p}$

JohnArthurReyes_1B
Posts: 18
Joined: Fri Sep 25, 2015 3:00 am

### 1.39

This problem required the mass of a neutron(1.673 * 10^-27) . This value wasn't explicitly given in the question. For future tests/quizzes would it be wise to memorize the mass of neutrons, electrons, and protons or are they given to us on a formula sheet?

Nicholas Codallos 4C
Posts: 19
Joined: Fri Sep 25, 2015 3:00 am

### Re: 1.39

The mass of an electron is on the formula sheet (back of the periodic table) however I don't see the mass of the protons and neutrons on the back, so I would recommend memorizing their values as a precaution. Furthermore memorizing the values could allow you to continuously work without stopping to reference the sheet, thus letting you work faster.