-
427 BCE
Plato
objects of matter have to derive atoms from 1 of 5 different solid objects. -
400 BCE
democritus
he thought that everything was made from atoms -
384 BCE
aristotle
he believed that everything was made out of the four atoms, earth fire water and air. he did not believe that things were made out of atoms. -
robert boyle
he believed that gas' volume decreases when pressure increases -
lavoisier
everything's total mass is always the same -
john dalton
he believed that atoms were the smallest particles of matter and also that they cannot be created or destroyed. also that all atoms of the same element were the same -
the alchemists
they made some parts of chemistry that is used today. some of it is instruments, some is what melts different substances. -
dmitri mendeleev
when all elements are put together in numerical order it can form a pattern -
robert millikan
quantifying an electrons charge -
JJ Thompson
found electrons -
photoelectric effect
when light with a certain energy hit a metal an electron may be locked loose -
einstein
einstein proved that atoms exist mathemathically he also proved liquids are made of molecules -
plancks quantum theory of light
the energy of light is proportional to the frequency -
the curies
they discovered polonium and radium -
ernest rutherford
atoms are mostly hollow and that the majortiy of their matter comes from the nucleus. -
henry g j moseley
the atomic numberis number of positive charges in the nucleus of an atom -
werner heisenberg
he developed the electron cloud model -
shrodinger equation
wave equation -
neils bohr
he created the model of the atom -
james chadwick
exsistance of neutrons