Question | Answer |
What is an isotope | An atom where the number of protons do not equal the number of neutrons |
What is matter made of | Atoms |
What are characteristics of atoms | They are indestructible and indivisible |
How are compounds formed | By a combination of two or more different kinds of atoms |
What is a chemical reaction | A rearrangement of atoms |
Atomic theory | All matter is made up of distinct, indivisible particles |
Mendelev | wrote first PT on a deck of playing cards |
Greek thinker, came up with "atomos" | Democrates |
Democrates | "if you separate something until it can't be divided anymore, the atomos will be indivisible, invisible, and homogeneous" |
said that atoms don't exist; matter is made of earth, fire, air, and water. (Theory wasn't disputed for a long time) | Aristotle |
John Dalton | Father of Modern Atomic Theory |
Says that atoms do exist, atoms are round empty balls that hook together | John Dalton |
Sir William Cookes | Discovered the electron by accident, in the absence of matter there are charged particles, cathode ray tube |
called electrons corpuscles, used the cathode ray tube, said that there were particles smaller than atoms | JJ Thompson |
JJ Thompson | plum pudding model |
Robert Milliken | oil drop experiment, measured the mass of an electron |
looked at other charges in the atom, Gold Foil Experiment | Ernest Rutherford |
Ernest Rutherford | refuted plum pudding model, discovered the positive charge and the nucleus |
James Chadwick | discovered the neutron, number of electrons= the number of protons |
came up with energy levels | Neils Bohr |