History Of The Atom Flashcards
What are atoms made of?
Protons, neutrons and electrons.
What are protons?
Positively charged particles found in the nucleus.
What are neutrons?
Neutral particles found in the nucleus.
What are electrons?
Negatively charged particles that orbit the nucleus.
What did Democritus discover?
Democritus is an Ancient Greek philosopher who was the first to propose the theory of the atoms in 400.B.C
What did John Dalton do?
He described the atoms as solid balls.
What did JJ Thomson do?
Concluded for his experiments that atoms arenโt solid spheres.
His measurements of charge and mass show that an atom contains smaller, negatively charged particles, later on named particles.
What did Rutherford do?
- That the atom is mostly empty space, majority of the mass coming from the nucleus.
- All of the positive charge comes from the nucleus
What did Chadwick do?
He discovered neutrons. He found out the neutron was neither positively or negatively charged but rather was neutral. He discovered that neutrons are located in the centre, inside the nucleus