Chapter 2 Flashcards
Law of Conservation of Mass
Mass is neither created nor destroyed
Law of Definite Proportions
Each compound has a specific ratio of elements
Law of Multiple Proportions
When the same elements form 2 or more different compounds
Particles that composed cathode rays are
negatively charged
All atoms contain the same particles…..
negatively charged electrons
Nuclear Forces
Short range attractions between protons and neutrons
Proton
p+
Neutron
n0
Electron
E-
Charge of the proton
1+
Charge of the electron
1-
Charge of the neutron
0
John Dalton
Came up with the atomic theory
Atoms being divided into smaller particles
nuclear fission
Cathode Ray Experiment
Done by JJ Thomson, led to the discovery of the electron
Conclusions of the cathode ray tube experiment
1) particles that compose cathode rays are negatively charged
2) all atoms regardless of the element contain electrons(negatively charged particles)
Gold Foil Experiment
Performed by Rutherford, shoots a beam of (positively charged) alpha particles at a piece of gold foil
Results of gold foil experiment
tells us that there is something dense and a positively charged mass inside of the nucleus
Chadwick
Discovered the neutron, used beryllium
Nuclear Forces
Attractions between protons and neutrons
Atomic Number =
number of protons/ number of electrons
Mass Number
Total number of protons and neutrons
isotopes have…
different masses
To find the number of neutrons…
mass number-atomic number
