Dalton
what did Dalton say atoms vary in?
size and mass
What part of the atom did Thomson discover
the electron
What part of the atom did Rutherford discover?
the nucleus
What did Bohr improve from a past scientist?
Rutherfords nuclear model
What two particles are in the nucleus of an atom?
Protons and neutrons
Name 1 atom postulate
- matter is made up of atoms that are indivisible and indestructible
- all atoms of an element are identical
- atoms of different elements have different weights and chemical properties.
- atoms of different elements combine in simple whole numbers to form compounds.
- atoms cannot be created or destroyed.
What model of the atom did Thomson propose
the plum pudding model
What did Rutherford disprove
the plum pudding model
What did he propose?
the Bohr model of the atom
Atoms of the same element with different numbers of neutrons are called this.
Isotopes
Atoms of the same element are ___
identical
What evidence did Thomson use to contribute to atomic theory
Cathode Ray tube experiment
what did Rutherford propose
the nuclear model of the atom
what did he find out about electrons?
they orbit the nucleus in their own energy levels
The number of protons in an atom determines this identifying number.
Name one thing Dalton did to contribute to atomic theory.
He created the rules of the atom.
What did Thomson reveal about atoms?
That they are not indivisible
what experiment/evidence did he use to reach his conclusions?
the gold foil experiment
What evidence did he use to reach his conclusions about the atom?
The hydrogen emission spectrum.
electron cloud
Dalton’s theory explained this law, which says compounds are made of elements in fixed ratios by mass.
the law of definite proportions
what did his work provide the foundation for?
subatomic particles
Even though it looked like the particles were passing straight through in his experiment, what were they doing instead?
they bounced off the positive atom
What did he find out about the electrons energy levels?
that electrons can only have one energy level, nothing in between.
What is the total number of protons and neutrons in the nucleus of an atom called?
the mass number