Radioactivity Flashcards
How big is an atom?
1 x 10^-10 m
What did Thompson discover?
Plum pudding model
What is the plum pudding model?
An atom is a ball of positive charge with negative electrons scattered throughout them.
What did Rutherford’s particle scattering experiment prove?
An atom had the mass focused in the centre (nucleus). That nucleus is positively charged.
How did Niels Bohr adapt the atom?
He suggested electrons orbit the nucleus at fixed distances.
What did Chadwick discover?
Neutrons
What is activity measured in?
Becquerels (Bq)
What is an alpha particle?
Has two neutrons, two protons, and a charge of 2+
What is a beta particle?
High speed electron ejected from the nucleus as a neutron and turns into a proton.
What is a gamma ray?
Electromagnetic radiation from the nucleus.
What is irradiation?
Process of exposing an object to nuclear radiation. An irradiated object does not become radioactive.
What is nuclear fission?
The splitting of a large unstable nucleus into two smaller daughter nucleus. Energy is released as well as excess fission neutrons
What is nuclear fusion?
The joining of two small nuclei to form a heavier nucleus. Large amounts of energy are released.
What conditions are needed for nuclear fusion?
High pressure and high temperatures are needed to overcome the electrostatic repulsion.
How are such high temperatures and pressures achieved for nuclear fusion?
Using strong magnetic fields and lasers
