Please enable JavaScript.
Coggle requires JavaScript to display documents.
Atoms - Coggle Diagram
Atoms
Scientists
Democritus
atoms are building blocks of matter
atoms are indivisible
Ernest Rutherford
gold foil experiment
found nucleus/proton
J.J. Thomson
found electron by cathode
Robert Milikan
oil drop experiment
1/1840 = mass of hydrogen
Chadwick
found neutron
Dalton's atomic theory
atoms in everything
atoms of same element are identical
atoms can combine with the atoms in simple ratios
chemical reactions rearrange the atoms, but don't change indentity
atomic number
number of protons
whole number
periodic table built on this
mass number
protons + neutrons
number of neutrons
mass number - atomic number
radiation types
alpha
2 protons and 2 neutrons
+
beta
charged electron
+/-
photon
gamma ray
no charge or weight
protons
postive charge
mass is 1840th of the electron
electrons
smallest
negative
isotopes
same atomic number w/ different number of neutrons
nuclide
atomic mass
1/12th of carbon 12 atom
weighted average of all the isotopes of an element
neutrons
neutral
law of conservation of mass
mass of reactants = mass of products
law of definite proportions
compound always contains the same elements in the same proportion of mass
law of multiple proportions
same 2 elements can be in a compound, but they must combine in different ratios
atoms are neutral