P1.1 Flashcards
Who created the first model of the atom and when
John Dalton in 1970
What was the model of John Dalton
The model of the atom was a small indestructible sphere
Characteristics of the first model
All atoms in an element are the same
The atoms in one element are different from the atoms in another element,
Who created the second model of the atom?
J.J thompson
How was it discovered
Discovered that cathode rays are made up of particles that have less than 1/ thousandth the mass of a hydrogen atom. He named it the electron
What was JJ thompson’s model called
The plum pudding model
What are the characteristics of the plum pudding model
The atom had a neutral charge so has negatively charged electrons embedded in a positively charge mass around them, this counteracts the charge of the electrons giving it a neutral charge.
Who created the third model of the atom?
Ernest Rutherford
How was the planetary created?
The model was created when he shot alpha particles (positively charged) at a one atom thick layer of gold foil. Most of the particles went straight through the gold foil but some were deflected.
Characteristics and reasons of the planetary model
The positive charge must be gathered in a very small place because so few were deflected.
The nucleus is small and dense because it deflects back.
The nucleus is positively charged as it repelled the alpha particles.
What was the model called
Planetary model
Characteristics of the planetary model
A positively charged nucleus which is orbited by electrons
What is the last model of the atom called?
The Bohr model
What are the characteristics of the Bohr model?
It was electrons in shells around charged nucleus of the atom. The nucleus is made up of neutrons and protons.
How was the Bohr model discovered?
It was discovered through mathematical calculations that showed that Rutherford’s model couldn’t exist as the electrons would spiral until they hit the nucleus
