Events
-Democritus was a Greek philosopher
who lived from 470-380 B.C, and is considered
the father of atomic thought. Democritus claimed
that all matter was made of small, indestructible
particles called ‘atomos’. This hypothesis was created
in 465 B.C-John Dalton was a British chemist
who was credited for pioneering
modern atomic theory in 1803
from experimenting with gases,
which led John Dalton to create
the first atomic model which
consisted of only a single ball,
with no protons, neutrons or
electrons as they had not yet
been discovered.-Frederick Soddy was an English chemist
who in 1912, hypothesised that elements
could exist in different forms, proposing
the idea of isotopes.-Max Planck was a German Theoretical Physicist
and considered the father of quantum theory,
as he created it in 1900. By discovering that
energy did not flow evenly but rather in packets
(which he called "quanta.") Planck created an
equation to predict this phenomenon, which
includes a constant now known as "Planck's
constant." Planck's discovery ended what many
people now call "classical physics" and began
the study of quantum physics.-J.J Thomson was responsible for the discovery of
the electron in 1897 using a cathode ray tube,
and proposed the ‘Plum Pudding’ atomic model
in 1904. The Plum Pudding atomic model consisted
of electrons within a positive atom.-Niels Bohr was a theoretical nuclear physicist.
Bohr proposed a theory in 1913 that electrons
existed in set orbits around the nucleus, and
was the key to the periodic repetition of
properties of the elements. Bohr improved
rutherford's model, making it so that electrons
orbited around the nucleus in a fixed manner-James Chadwick was an English Physicist who
was responsible for discovering the neutron in
1932 by using scattering data to calculate the
mass of the neutral particle.-Ernest Rutherford was responsible for creating
the Rutherford atomic structure in 1911 by
making the discovery that nearly the total mass
of the atom was located in the nucleus.
Rutherford discovered this using his well known
gold-foil experiment, demonstrating that the
atom has a heavy nucleus. Rutherford's atomic
structure consisted of a positively charged
nucleus orbited by electrons
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