UNIT 3 TEST REVIEW Flashcards
Dalton
FATHER OF THE MODERN ATOMIC THEORY
- All matter is made of atoms
- Atoms of the same element are identical( wrong)
- Atoms of different elements can physically mix together
- Chemical reactions occur when atoms are separated
Democritus of Abdera
Created the idea of the tiny fundamental particles that make up all matter: the atom
Sir william crookes
Cathode ray tube
Jj. Thomson
Discovered the electron (1897)
-pudding model
Rutherford
Discovered the nucleus- shot alpha particles (+charges) at a very thin piece of gold foil called the “gold foil experiment” rays rebounded back
Chadwick
Discovered the neutron
Bohr model
Only worked for hydrogen
Levels of electrons
What if they lose or gain electrons.
Ion=an atom or group of atoms that gains pr loses electrons. Charges are used to indicate whether it is a positive or negative ion.
- +=cation
- -=anion
Mendeleev
FATHER OF THE PERIODIC TABLE
The properties of elements are repeated according to their atomic mass
Mosley
Determined the number of protons in each element by bouncing X-rays on metal targets. Therefore today is arranged by the number of protons or atomic number
Electron
Takes up most of the volume of the atom
Z
Atomic #
A
Mass #
Sum of protons and neutrons in nucleus
X
Chemical symbol or name
Attractions
- +-+
- O-+
- O-O