Giants of Chemistry:
Democritus & Amedeo Avogadro
By Allison Combs and Arianna Guehl
Democritus
Back ground
●
●
●
●
●
●
●
●
●
Born in 460 BCE
Died in 370 BCE
Born in Abdera, Greece
Studied Astronomy, Theology and The Atomic Theory
Went to Athens, studied under Anaxagoras
Instructed in Pythagoreanism
Was a disciple of Leucippus
Also studied in Egypt, Ethiopia, Persia, and India
Nickname was “the laughing philosopher” for his
cheerfulness.
Major contributions to science and chemistry
●
●
●
●
●
●
Founded the atomic theory of matter (matter was composed
of fundamentally invisible particles, called “atomos”)
Believed atoms are invisible, all are exactly alike, and
all matter is made up of atoms.
Created the term atom.
Atoms to be eternal with their motion and the space where
the moved.
Atoms cannot be erased or deleted merely changed.
Atoms can change into any size or composition.
Politics and Controversy
●
●
Failed to please those who explained the world by a
divine power.
Socrates, Plato, and Aristotle all disagreed with
Democritus’ ideas.
Writings/ Books
He has 60 or so works. Few of his of ethical theories
remain. The fragments and descriptions of other writers add
him to be one of the foremost thinkers of his time. Plato
wanted to burn all works of Democritus but could not because
they were already widely circulated, according to
Aristoxenus. Many of his works were destroyed over the
years.
Contributions
Neil Bohr and J. Robert Oppenheimer had different work and
outcomes by basic ideas of the atom. Attempts of the atomic
bomb could not have been created if Democritus did not the
first basic rules of the atom.
Amedeo avogadro
Who was Amedeo avogadro?
●
●
●
●
●
●
Amedeo Avogadro was born in Turin, Italy on August 9,
1776
His real name is Lorenzo Roman Amedeo Carlo Avogadro di
Quaregna e di Cerreto
He was awarded a doctorate in canon law at the age of 20
and started working as an ecclesiastical lawyer
Soon after, he became interested in positive philosophy
(now called mathematics and physics).
He died at the age of 79 on July 9th, 1856.
He is known as the founder of the atomic molecular theory
Avogadro’s contributions
●
●
●
●
Amedeo’s interest in math and physics blossomed with the help of
Vassalli Eandi, a mathematical physicist.
In 1811, he wrote a paper in the Journal de Physique, explaining
his hypothesis that elements could exist as molecules, rather
than individual atoms. He also stated in this paper that a
volume of a gas is proportional to the number of atoms or
molecules regardless of the nature of it. This is known as
Avogadro’s Constant, or Avogadro’s Law
In his lifetime, Avogadro published many papers, all geared
towards proving his original hypothesis
6.02214086 × 10 mol
23
-1
Controversy
●
●
●
Many well known scientists at the time, such as Dalton,
and Berzelius, disagreed with Avogadro’s work.
The Journal de Physique wasn’t a well read scientific
journal
Many people believed that Italy wasn’t a country where
great scientific work occurred.
Contributions
●
●
The value of Avogadro’s constant was first indicated in
1865 by Johann Josef Loschmidt by estimating the average
diameter of molecules in the air
In 1909, French physicist, Jean Perrin proposed naming
the constant after Avogadro. In 1926, he won a Nobel
Peace Prize for determining the value of the constant in
several different ways