Swedish scientist who developed the theory of electrolytic dissociation (or ionization) and won the Nobel Prize for chemistry in 1903.

Italian who developed a law of gases (1811): equal volumes of all gases at the same temperature and pressure contain equal numbers of molecules; he coined the term molecule and is regarded as one of the founders of physical chemistry.

English 'Founder of Experimental Science' who laid the foundation for the experimental method of chemical research and finished his Opus mius (Longer Work) about 1267.

Scottish scientist who defined specific heat in the 18th century and formed the concept of latent heat and showed that carbon dioxide differs from ordinary air.

Danish developer of a theory of atomic structure (1913).

Irish 'Father of Chemistry' who developed his law of gases (volume of a gas at constant temperature varies inversely with pressure) and was the first to separate chemistry from alchemy and the first to clearly define a chemical element; he wrote Sceptical Chymist (1661).

Danish scientist known for his theory on acids and bases (1922).

German who developed the foundations of spectroscopy (1859) with Gustav Kirchnoff, developed a burner (1855), and discovered cesium and rubidium.

English scientist who discovered the properties of hydrogen (1766), describing it as 'inflammable air,' and showed that water is a compound of oxygen and hydrogen.

French scientist who discovered the law stating that different gasses all expand by the same amount with a given rise in temperature; since he didn't publish, this law is usually named after another Frenchman.

Polish-French discoverer of radium and polonium while working in conjunction with her husband and Henri Becquerel; first person to be honored with 2 Nobel Prizes, physics and chemistry.

English scientist who formulated the law of partial pressure in gases (1802) and developed the atomic theory and explained its application (1803).

English scientist who discovered the chemical elements sodium, potassium, magnesium, barium, calcium, and strontium in the early 19th century.

Greek who developed a theory that the world consisted of tiny, indivisible particles called atoms.

Greek who believed that there were 4 elements: earth, air, fire, and water.

English discoverer of a mathematical relationship between electricity and the valence of a chemical element; these laws of electrolysis bear his name, and he was a pioneer in the liquefication of gases.

French pioneer in gases who formulated the law that for a given amount of gas held at constant volume, the pressure is proportional to the absolute temperature; he was the first to isolate the element boron and to introduce the terms pipette and burette.

Scottish founder of colloid chemistry, a principal founder of physical chemistry, and is known for a law of diffusion (1833).

German who invented a process of producing ammonia from nitrogen and hydrogen for which he won the Nobel Prize in chemistry in 1918.

German who received the Nobel Prize for chemistry in 1944 for the discovery of the fission of heavy nuclei.

German sometimes called the 'Father of Analytic Chemistry' who discovered uranium and zirconium (1789).

French 'Father of Modern Chemistry' who wrote the first modern textbook of chemistry, Elementary Treatise on Chemistry (1789); he discovered the role of oxygen in combustion and respiration, named this gas, and overthrew G.E. Stahl's theory on combustion.

French scientist known for a principle or law concerning stress applied to a system at equilibrium; if a chemical system at equilibrium experiences a change in concentration, temperature, volume, or partial pressure, then the equilibrium shifts to counteract the imposed change and a new equilibrium is established.

American who helped others understand thermodynamics, chemical bonding, and acid base theory.

English physician who introduced antiseptic surgery and was named a baron, making him the first medical man to be elevated to the British peerage.

Russian who devised the periodic table and wrote Elements of Chemistry (1868).

French founder of microbiology, laid the foundation of the germ theory of disease, developed pasteurization and a vaccine against rabies (1885), and is considered the founder of preventative medicine.

American who won the Nobel Prize for chemistry in 1954 for his research into the nature of the chemical bond.

English scientist who discovered 9 gases in all, including nitrogen, sulfur dioxide, and laughing gas, and shares credit for the discovery of oxygen (1774) with Sweden's Carl William Scheele; he called oxygen 'dephlogisticated air.'

First American chemist to receive the Nobel Prize (1914) for his exact determination of the atomic weights of chemical elements.

New Zealand born, British 'Father of Nuclear Science' who discovered 2 types of radioactivity, naming them alpha decay and beta decay, developed the theory of the atom (1911), became the first person to break up the nucleus of an atom (1919), and won the Nobel Prize in chemistry in 1908 for discovering that radioactive elements change into other elements.

Swedish scientist who discovered oxygen (1771) and chlorine (1774), molybdenum (1778), manganese, tungsten, and other chemical elements and substances.

American who shared the Nobel Prize for chemistry in 1951 with Edwin M. McMillan for the discoveries in the chemistry of transuranium elements; he co-discovered elements with atomic numbers 94-102 of the periodic table, discoveries that were made with the aid of a cyclotron.

Founder of Greek Science, Mathematics, and Philosophy who believed that water was the one element from which the world was formed.

American who won the Nobel Prize in chemistry in 1934 for the discovery of deuterium ('heavy water'), a rare hydrogen isotope.

German who founded the science of organic chemistry and synthesized organic compounds from inorganic material (1828), thus refuting the prevailing 'vital force' theory.