Key Concepts in Chemistry- Year 10 topic 1 Flashcards
Who first developed the idea that matter was made out of particles and in what year did they do so?
Democritus- 400BC
In 1803 what did John Dalton predict?
Atoms were tiny particles that made up elements that could not be divided.
Who discovered the electron in 1897?
JJ Thompson
What model did JJ Thompson devise in 1904 that showed negative electrons moving in a sea of positive charge?
Plum pudding model
What did Rutherford propose and what what year did he do so?
Nuclear atom in 1911
Why did Bohr alter Rutherford’s model?
So electrons could follow certain paths
Who discovered a neutral particle and what was the neutral particle?
James Chadwick and the neutron
Why are atoms neutral?
Because protons and electrons are balanced in charge
What is an isotope?
An isotope is when different atoms of the same element containing the same number of protons but different numbers of neutrons in the nucleus.
