Topic 1 - History of the atom and electronic structure Flashcards
What did J J Thomson discover about atoms.
They weren’t solid spheres and they contained smaller particles called electrons. He created the “plum pudding model” which showed an atom as a ball of positive charge with electrons stuck in it.
How did Ernest Rutherford show the Plum Pudding model was wrong?
The alpha particle scattering experiments: He fired charge alpha particles at a thin sheet of gold and some were deflected so the model couldn’t be right.
What was Rutherford’s nuclear model?
A positively charged nucleus was at the center and a cloud of negatively charge electrons surrounded this.
What did Niels Bohr discover about the atom?
He discovered that the electron were arrange in shells which orbit the nucleus.
After Bohr’s discovery, what did further experiments show?
They showed the existence of protons inside the nucleus with positive charges.
What did James Chadwick discover about the atom?
He found evidence for the existence of neutral particles called neutrons.
How many electrons are there in the first energy level?
2
How many electrons are there in the energy levels (not including the first)?
8
