The Atom Flashcards
Who was john dalton
Summarized matter- dalton atomic theory
Define matter
All matter is made up of small particles called atoms
Define atoms
Are indivisible, cannot be split into simpler particles by chemical means
Who. Was William crookes.
Discovered cathode rays by placing an electric current through glass tube under low pressure
What are cathode rays
Negatively charged streams of particles called electrons
What did the Maltese cross do
Deducted that cathode rays travel in straight lines
Cathode rays cause glass to flourese when they hit it
Who was just Thompson
Measured if cathode rays had a charge
What is an energy level
The fixed energy value that an electron in an atom may have.
State aufbaou principle
When building electronic configurations of an atom in its ground state, electrons occupy the lowest energy levels first
State hounds rule principle
When two or more orbitals of equal energy are available, electrons occupy them singly before in pairs.
State Pauli exclusion principle.
States that no more than 2 electrons can occupy an orbit and they must have an opposite spin.
