Prelims - Nucleus

Center of the atom and contains the protons and neutrons.

Protons and neutrons are collectively known as

The number of _____ determines the element

The number of neutron is always _____ that the number of protons.

Protons and neutrons are made up of combination of

Charge of up quark

Charge of down quark

Protons contain 3 valence quarks

Neutrons contain 3 valence quarks

Assumes a spherical nucleus composed of closely packed nucleons.

Liquid Drop Model is introduced by who?

Protons and neutrons occupy shells and subshells that are arranged in discrete energy shells.

Shell Model is introduced by who?

is the work (energy) required to overcome the strong nuclear force.

is the difference between the sum of the masses of all nucleons to the measured mass of the nucleus. The energy equivalence of this mass is equal to the nuclear binding energy.

Mass-Energy relationship in nucleus

There are very large repulsive electrostatic forces between protons which should cause the nucleus to fly apart

The nuclei are stable because of the presence of a shortrange

up to atomic number 82 (lead)

technetium (Z = 43) and promethium (Z = 61)

Larger atoms (Z > 83)

Neutron-Proton ratio chart

charge of a nucleus

natural occurrences in isotopes that are particularly stable, and include Z = 2, 8, 20, 28, 50, 82, 114 N = 2, 8, 20, 28, 50, 82, 126, 184

Nuclear binding energy typically ranges from 6 to 9 MeV

In nuclear reactions, any change in the mass of the nuclei has an associated change in its energy

Lead with an atomic number of 82 is unstable

In larger atoms, protons exceed the number of neutrons

Protons and neutrnos are no longer believed to be a fundamental principle

Neutrons contain 2 up quark and 1 down quark

Nucleus with 2, 8, 20, 50, 82, or 126 protons or neutrons are considered unstable nucleus