Nuclear Mass and Energy

The Nucleus – made up of protons and neutrons (nucleons)       The electrons are out side of the nucleus.    

See more diagrams at: http://www. bmb. psu

What is the Electron Cloud Model?

What is the Electron Cloud Model? Diagram 1:

What is the Electron Cloud Model? Model of the atom pictures the electrons moving around the nucleus in a region called an electron cloud. For more information, click here: http://regentsprep.org/Regents/physics/phys05/catomodel/cloud.htm

The electron cloud is a cloud of varying density surrounding the nucleus. The varying density shows where an electron is more or less likely to be. Atoms with electrons in higher energy levels have additional electron clouds of different shapes that also show where those electrons are likely to be. For more information, click here: http://regentsprep.org/Regents/physics/phys05/catomodel/cloud.htm

What is the Electron Cloud Model? Diagram 2: This diagrams shows regions of space where electrons are most likely to be found = orbitals

http://www.bmb.psu.edu/courses/bisci004a/chem/atoms.jpg

The mass of an atom is measured in terms of universal mass units (u) (in chemistry we called them atomic mass units (u))   one universal mass unit = 1.66 x 10-27 kg see reference table Using textbook value 1u = 1.6605 x 10-27 kg

What is the mass of a proton in universal mass units? Mass of a proton = 1.67 x 10-27 kg Mass of a proton = 1.67 x 10-27 kg = 1.007276 u

What is the mass of a neutron in universal mass units? Mass of a neutron = 1.67 x 10 -27 kg Mass of a neutron = 1.67 x 10 -27 kg = 1.008665 u

What is the mass of an electron in universal mass units? Mass of electron = 9.11 x 10 -31 kg Mass of electron = 9.11 x 10 -31 kg = 0.0005487 u

a proton plus an electron = 1.007825 u From the text book use: Mass of most abundant hydrogen isotope hydrogen -1 H-1 a proton plus an electron = 1.007825 u

Einstein showed that mass and energy are different forms of the same thing. Energy equivalent to mass is directly proportional to both the mass and the speed of light in a vacuum squared.  

E = mc2 E = energy m = mass c = speed of light in air or vacuum Listen to Einstein talk about E=mc2 55 seconds Weasel Apparently Shuts Down World's Most Powerful Particle Collider – NPR story April 29, 2016

Answer the following using the “u” mass values given above for the subatomic particles.   If the mass of a neutron were converted into energy the yield would be? If the mass of a beta particle were converted into energy the yield would be?

Answer the following using the “u” mass values given above for the subatomic particles.   If the mass of a neutron were converted into energy the yield would be? 1 neutron = If the mass of a beta particle were converted into energy the yield would be?

The nuclear force is an attractive force between the protons and the neutrons that holds the nucleus together. Nuclear forces are the strongest forces known to exist, but they are only effective over a short distance. Where does this energy come from?

  Mass Defect – the difference between the sum of the masses of the individual particles (protons, neutrons and electrons) and the actual measured mass. Binding energy and fission cartoon video 2:57 Nuclear Binding Energy and the Mass Defect a reference data table

Mass Defect (See example problem p804, do practice problems #5-8 on p 805)

Describe Isotope Example: http://education.jlab.org/glossary/isotope.html