Nuclear Physics Flashcards
3 isotopes of hydrogen
(1 1) Protium
(1 2) Deuterium
(1e 3) Tritium
Fissile material
Material that can undergo the fission reaction
The Rutherford model
A gold leaf experiment conducted in 1909 by Hans Geiger and Ernest Marsden in which alpha particles were fired at a thin gold leaf (1000 atoms thick). About 1/8000 particles hit the very small, surrounded mostly by empty space, nucleus(containing most of the mass) and were deflected due to the like charge of the alpha particles and protons in the nucleus.
The atoms far away would be unaffected by the forces and continue in a straight path, those closer would be deflected, and closer would completely turn around
Atom
Smallest unit of matter that still retains the chemical properties of its elements
Structure of an atom
Consists of a central, positive nucleus containing protons and neutrons, orbited by shells/orbitals carrying negative electrons.
What is this referred to as
A=
X=
Z=
Nucleic notation
A = (big no.) atomic mass/nucleon no.
X= element symbol
Z= proton/atomic mass
Isotopes
Atoms with the same number of protons but different mass numbers. Most radioactive elements exist as isotopes
What happens during nuclear processes
The proton and atomic mass number are conserved
The H represents an alpha particle and nuclear radiation
What prevents electrons from falling into the nucleus
Their speed
Proton number
Number of protons in a nucleus
Proton charge
1.6x10*-19
Nucleon number
Number of protons and neutrons in an atomic nucleus
Isotope
Same proton number different mass number
Nuclide
Species of nucleus having particular values of proton and nucleon numbet
2 isotopes of helium
3/2 -rare
4/2 - commonest
What does it mean when an isotope is unstable
It undergoes radioactive decay, emitting radiation as it changes from one element to another
Nuclear fission
When a heavier nucleus divides into 2 smaller ones. Induced by an introduction of a neutron as the neutron has no charge and is not deflected by the positively charged protons in the nucleus.
Radioactive decay
The decay of a radioactive substance when its atomic nuclei emit radiation (to become stable?)