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Atoms - Coggle Diagram
Atoms
History of our Knowledge
Ernest Rutherford
Discovered the nucleus in gold foil experiment
James Chadwick
Discovered the neutron
J.J. Thomson
Discovered the electron using cathode ray
John Dalton
Made Atomic Theory
Atoms of the same element are identical
Isotopes disprove this
atoms can combine with other atoms in simple ratios
Atoms are in everything
Chemical reactions rearrange the atoms but don't change their identity.
Democritus
First person to theorize about the concept of an atom
Laws
Law of Definite Proportions
A compound always contains the same elements in the same proportion by mass
Law of Multiple Proportions
The same 2 elements can be in a compound, but they must combine in different ratios
Law of Conservation of Mass
Mass of reactants = mass of products
Periodic Table
Isotope
Same atomic #, different # of neutrons
nuclide - nucleus of any element
Mass #
Protons + neutrons
Number of neutrons = mass # - atomic #
Atomic #
Number of Protons
Periodic table built on this number
Atomic mass
1 amu = 1/12 of a carbon atom
weighted average of all the isotopes of an element
Subatomic particles
Neutrons
Neutral charge
Adds to Mass #
Located in nucleus
Protons
Determines element
Positive Charge
Number of Protons = Atomic #
Adds to mass #
In nucleus
Electrons
Negative Charge
Orbits around nucleus
Radiation
Alpha particle
2 protons and 2 neutrons
Helium nucleus
Outside of body: harmless
Inside: bad for soft tissue
Beta particle
neutron changes to proton, releases energy (electron)
Charged electron
Gamma Ray
Photon, pure energy
No weight or charge