The Chemists and Their Discoveries

Dmitri Mendeleev

• Arranged the elements on the periodic table based on atomic mass

• Arranged the elements on the periodic table based on atomic number

Niels Bohr

• Nuclear Model; Gold Foil experiment allowed him to discover that the nucleus

  was the positively charged center of the atom surround by negatively charged electrons

• Electrons travel in fixed orbits around the nucleus of the atom

Schrodinger and

Heisenberg

• Electrons travel in fixed orbits around the nucleus of the atom

• Electron Cloud Model; surrounding the nucleus is an electron cloud made of

  shells - electrons do not, however, travel in a fixed orbit

Ernest Rutherford

• Named the atom based on the Greek word meaning indivisible

• Nuclear Model; Gold Foil experiment allowed him to discover that the nucleus

  was the positively charged center of the atom surround by negatively charged

  electrons

Dalton

• Arranged the elements on the periodic table based on atomic number

• Solid Sphere Model; elements are atoms with different masses

Democritus

• Named the atom based on the Greek word meaning indivisible

• Arranged the elements on the periodic table based on atomic mass

JJ Thomson

• Plum Pudding Model; atom is positive sphere with negatively charged particles

  evenly embedded throughout

• Arranged the elements on the periodic table based on atomic mass