Atomic Theory And Models Flashcards
What is the Plum Pudding model?
Atoms are made mostly out of positively charged material, like dough in a bun. The negatively charged electrons are found inside the positive dough
Who created the Plum Pudding model?
JJ Thomson
When did Thomson’s introduce his theory?
1897
What did Democritus contribute to the atomic theory?
He said:
Matter is formed of small pieces that could not be cut into smaller parts called atomos meaning uncuttable
When did Democritus introduce his theory?
430 BC
What information did John Dalton contribute to the atomic theory?
1) Atoms are tiny,invisible particles
2) Atoms of one element are all the same
3) Atoms of different elements are different
4) Compounds form by combining atoms
When did John Dalton introduce his theory?
1808
The positively charged particle in an atom
Proton
What is a proton?
The positively charged particles in the nucleus
Atom model
A representation of an Atom (a picture of what the atomic theories explain)
Atom
The smallest particle in which an element can be divided and still be the same substance
John Dalton
British Chemist who developed his atomic theory gathered from observations gathered during his experiment.
Electron
The negatively charged particles in an atom that are involved in the formation of chemical bonds
Particle
A tiny piece or part
Nucleus
The tiny extremely dense positively charged region in the center of an atom, made of protons and neutrons
Bohr Model
The model of the atom that states that electrons move around the center of the atom’s nucleus in fixed orbit; also called the planetary model
Ernest Rutherford
Scientist Who stated that the atom was mostly empty space in at the center was a small dense positively charged nucleus
Neils Bohr
Danish Scientist who suggested that electrons travel around the nucleus in fixed paths
Fixed orbit
To revolve around an object in a fixed path
Neutron
The particles of the nucleus that have no charge
Quarks
The subatomic particles that make up protons, electrons, and neutrons.
Subatomic particle
Any particles that are smaller than an atom
Electron cloud
The regions inside an atom where electrons are likely to be found
Mass number
The sum of the protons and neutrons in an atom