Slides in this set
384- 320 BC
Antione- Laurent de Laviosier
Jons Jakob Berzelius
Johann Wolfgang 1862
Dobheriener Alexandre- Emilie Beguyer de
Dmitri Mendeleev Lothar Meyer…read more
He believed that they were only 4 elements which made up the world; earth,
water, air and fire.
Three of these are examples of what we call the three states of matter; solid,
liquid and gas.
The fourth, fire, is similar to what we now call plasma.…read more
ANTIONE-LAURENT DE LAVOISIER
In 1789, Lavoisier and his wife wrote the first modern chemical textbook.
In his Traite Elementaire de Chimie he complied the first extensive lsit of
elements, which we described as substances that could not be broken down
further. His list contained 33 elements.
He also distinguished between metals and non-metals.
He devised a theory for the formation of compounds from elements.…read more
JONS JAKOB BERZELIUS
In 1828, he published a table of atomic weights, and determined the composition
by mass of many compounds.
He was also responsible for introducing letter based symbols for elements.…read more
JOHANN WOLFGANG DOBHEREINER
In 1829 Dobhereiner proposed his `Law of Triads' stating that-
"Nature contains triads of elements where the middles element
Has properties that are an average of the other two members of the
Triad when ordered by the atomic weight"
Developed triads, groups of 3 elements with similar properties-
Lithium, Sodium and Potassium formed a triad.
Calcium, Strontium and Barium formed a triad.
Chlorine, Bromine and Iodine formed a triad.…read more