A proton weighs 1.007276 amu , a neutron weighs 1.008665 amu, and an electron weighs 5.486×10−4 amu. What is the expected mass of a beryllium-9 nucleus, based on the total mass of its protons and neutrons?

1 Answer
anor277
Jun 12, 2016

This question is similar to "you buy 5 lemons at $0.33 each and 5 oranges at $0.45 each. How much change do you have from $5-00 ?#

Explanation:

You have a #""^9Be# atom, #Z=5#. There are 5 protons, and 4 neutrons, and 5 electrons. Why?

#"Mass"# #=# #(5xx1.007276+4xx1.008665+5xx5.486xx10^-4)" amu"# #=# #??" amu"#.

The mass of the electron is probably insignificant with respect to the mass of the nuclides. It would not be with respect to the binding energy, which I suppose is the next question.

You might have got a quicker and more sophisticated answer in the physics forum.

Related questions
See all questions in Nuclear Chemistry
Impact of this question
6431 views around the world
You can reuse this answer
Creative Commons License