atom models Flashcards
1
Q
what did democritus propose about matter
A
all matter is composed of small invisible particles
2
Q
what were some of john daltons idea
A
- all matter is made up of hard invisible particles called atoms
- atoms of the same elements are identical
- atoms of different elements are different so they are unique
- compounds are formed when atoms are combined in a ratio
- atoms cannot be created or destroyed
3
Q
describe j.j thompson’s theories
A
- found that electrical charge is composed of small negatively charged particles
- electrons of substances all have the same mass and charge
- electrons and protons are evenly distributed
- raisin cake idea
4
Q
what did henri becquerel discover
A
- radioactive materials released 3 types of radiation
- atoms cannot be created or destroyed
5
Q
what was rutherford famous for
A
- gold foil experiment with radioactive particles
- purpose was to determine where the protons were located in an atom
6
Q
what did bohr discover
A
- total energy if an electron is quantized
- electrons move around in one of several energy levels
7
Q
who presented the wave mechanical model
A
erwin schrodinger
8
Q
who discovered the neutron
A
james chadwick
