chemistry

Aristotle

340

https://www.youtube.com/watch?v=lP57gEWcisYOne of the most influential philosophers. • Wrote extensively on many subjects, including politics, ethics, nature, physics, and astronomy. • Most of his writings have been lost through the ages.

Democritus

400

https://www.youtube.com/watch?v=_lNF3_30lUE• Matter is composed of empty space through which atoms move. • Atoms are solid, homogeneous, indestructible, and indivisible. • Different kinds of atoms have different sizes and shapes. • The differing properties of matter are due to the size, shape, and movement of atoms. • Apparent changes in matter result from changes in the groupings of atoms and not from changes in the atoms themselves.

Antonie Lavosier

Oct 2, 1790

https://www.youtube.com/watch?v=zUDDiWtFtEMcompiled a list of all the known elements at the time.

Joseph Proust

Oct 2, 1799

came up with the constant composition, stating that chemical compounds always combine in constant proportions

William Crookes

Oct 2, 1800

noticed a flash produced by some form of radiation striking a light-producing coating that had been applied to the end of the tube, thus discovering the cathode ray

John Dalton

Oct 2, 1802

https://www.youtube.com/watch?v=sRPejoNktKEhttps://www.youtube.com/watch?v=sRPejoNktKE(Atomic theory) All matter is composed of extremely small particles called atoms. • All atoms of a given element are identical, having the same size, mass, and chemical properties. Atoms of a specific element are different from those of any other element. • Atoms cannot be created, divided into smaller particles, or destroyed. • Different atoms combine in simple whole number ratios to form compounds. • In a chemical reaction, atoms are separated, combined, or rearranged.

Amadeo Avagadro

Oct 2, 1811

contributions to molecular theory, including what is known as Avogadro's law. which states that equal volumes of all gases, at the same temperature and pressure, have the same number of molecules

charles goodyear

Oct 2, 1839

American inventor Charles Goodyear accidentally heated a mixture of natural rubber and sulfur. The resulting reaction greatly strengthened the rubber.

J.J. Thomson

Oct 2, 1890

began a series of cathode ray tube experiments in the late 1890s to determine the ratio of its charge to its mass. By carefully measuring the effect of both magnetic and electric fields on a cathode ray, Thomson was able to determine the charge-to-mass ratio of the charged particle. concluded that the mass of the charged particle was much less than that of a hydrogen atom

Henri Becquerel

Oct 2, 1897

By accident, he discovered that the uranium salts spontaneously emitted a penetrating radiation that could be registered on a photographic plate

Madame Curie

Oct 2, 1898

discovered radioactivity, and conducted pioneering research on radioactivity.

Max Planck

Oct 2, 1900

originated quantum theory

G. N. Lewis

Oct 2, 1902

devised the electron dot structur while teaching a college chemistry class

Albert Einstein

Oct 2, 1905

proposed that a photon is a particle of electromagnetic radiation with no mass that carries a quantum of energy, therefore electromagnetic radiation has both wavelike and particle-like natures

Robert Millikan

Oct 2, 1909

determined the charge of an electron.

Ernest Rutherford

Oct 2, 1911

studied how positively charged alpha particles interacted with solid matter.

Henry Moseley

Oct 2, 1913

discovered that atoms of each element contain a unique positive charge in their nuclei. Thus, the number of protons in an atom identifies it as an atom of a particular element

Niels Bohr

Oct 2, 1913

proposed a quantum model for the hydrogen atom

Louis deBroglie

Oct 2, 1924

proposed an idea that eventually accounted for the fixed energy levels of Bohr’s model.

Erwin Schrodinger

Oct 2, 1926

https://www.youtube.com/watch?v=Q_h4IoPJXZw furthered the wave-particle theory proposed by de Broglie.

Werner Heisenberg

Oct 2, 1927

concluded that it is impossible to make any measurement on an object without disturbing the object.

James Chadwick

Oct 2, 1932

https://www.youtube.com/watch?v=LdWonERbS7Yshowed that the nucleus also contained another subatomic particle, a neutral particle called the neutron

my dads bday

Oct 2, 1971

my moms bday

Oct 2, 1976

madelines bday

Oct 2, 1997

my bday!!

Mar 9, 1999

on this beautiful day a wonderful baby boy was born #fantastic

samuels bday

Oct 2, 2001

henrys bday

Oct 2, 2004

annas bday

Oct 2, 2006

kates bday

Oct 2, 2012