Chapters 4&5 Flashcards
What did Democritus contribute?
The idea of indivisible atoms
What are models used for?
To observe things too big, too small, too complex, the relationships among various objects, and things that are difficult to observe.
What did John Dalton contribute?
- ) Elements are made up of indivisible atoms which can’t be changed into other elements
- ) Atoms of the same element are exactly alike
- ) Atoms of different elements can join different to form different compounds
Was John Daltons theory correct?
No
What did JJ Thompson contribute?
- The Plum Pudding
- The idea of electrons
What did Ernest Rutherford contribute?
- The idea of a Nucleus
- Gold Foil Experiment
What are the charges of Protons, Nuetrons, and Electrons?
Positive, Neutral, and Negative
How do you find the numbers of Nuetrons in an atom?
Mass # - Atomic #
What are isotopes?
An element with the same number of Protons but with a different number of Nuetrons
What did Neil’s Bohr contribute?
The idea that electrons orbit in circular orbits around the nucleus like planets
What must happen to an electron if it moves into a higher/lower energy level
It must gain/lose energy
Was Bohrs model correct?
No
What did Erwin Schrooder contribute?
The Electron Cloud Model (The Quantum Mechanical Model)
What is the Electron Cloud Model?
The regions in an atom where electrons are found called orbitals. Theses orbitals are clouds of probability where electrons may be found
What is a Valence Electron?
Electrons in the outermost shell of an atom
