Background Radiation is noise radiation ( static ) that is evenly spread across space. C.O.B.E satellite confirmed that it is evenly spread.
Elements in the Universe
The universe cooled down and that's when some elements were created, such as hydrogen and helium which are the most abundant elements in the universe.
Main alternative to the Big Bang Theory of the universe is called Steady State Theory which in the universe does not change very much within time.
Models of the Atom
His atomic theory was that matter is composed of very tiny particles.
Cathode ray tube
Rutherford's gold foil experiment
This experiment was a radioactive element that emitted alpha particles which was directed toward a thin sheet of gold foil that was surrounded by a screen which would allow detection of the deflated particles.
The Bohr model has a positive charge and electrons orbiting around it.