A-Level Physics OCR A H556

6.4.1: The nuclear atom

#6.4.1a

alpha-particle scattering experiment; evidence of a small charged nucleus

#6.4.1b

simple nuclear model of the atom; protons, neutrons and electrons

#6.4.1c

relative sizes of atom and nucleus

#6.4.1d

proton number; nucleon number; isotopes; notation $^A_ZX$ for the representation of nuclei

#6.4.1e

strong nuclear force; short-range nature of the force; attractive to about 3 fm and repulsive below about 0.5 fm

1 fm = 10^–15 m

#6.4.1f

radius of nuclei; $R = r_0A^{1/3}$ where r₀ is a constant and A is the nucleon number

#6.4.1g

mean densities of atoms and nuclei.

6.3.3

Electromagnetism

6.4.2

Fundamental particles