Lecture 2: Review of Nuclear Physics

1 AMU is equivalent to how many g/mol?

1

If an nuclide has the same number of protons but a different number of neutrons, it is an …

isotope

If an nuclide has the same number of neutrons but a different number of protons, it is an …

isotone

If an nuclide has the same mass number but a different number of neutrons and protons, it is an …

isobar

1 AMU is equivalent to how much MeV/c²?

931.5 (E=mc²)

Proton AMU

1.0073

Neutron AMU

1.0087

Electron AMU

0.0005

Approximately, how much bigger is an electron compared to a proton or neutron?

~ 1800

What forces bind atoms?

the nucleus of an atom is held together by the strong force, while the electrons are held in the atom by the electric force

EM force

Any particle with electric charge will exert a force on any other particle with charge.

1. Opposite charges attract; like charges repel.

2. The force gets weaker as the two charges get farther apart.

Strong Nuclear Force

Attracts protons to protons, neutrons to neutrons, and protons and neutrons to each other. The force has a very short range (this is why the nucleus of an atom is so small)

Mass Excess

atomic mass minus the atomic mass number (M-A)

mass defect

sum of mass of individual components of the atom minus the mass of the entire atom

binding energy

mass defect multiplied by the square of the speed of light

Q-value

mass before minus mass after

What type of reaction has a positive Q-value?

exergonic

If a nuclide has a higher binding energy per nucleon, is the nuclei more or less stable?

More stable (lower energy)

What terms are part of the semi-empirical mass equation?

volume, asymmetry, coulomb, surface effect, pairing

What are the magic numbers for extra stability?

2, 8, 14, 20, 28, 50, 82, 126 (neutrons or protons)