Scientists quiz 10/30/25

Democritus

Developed the concept of the atom

John Dalton

Developed the atomic theory & law of multiple proportions
- atomic theory: all matter is made of atoms
- law of multiple proportions: when two elements combine to form more than one compound, the masses of one element that combine with a fixed mass of the other are in a ratio of small whole numbers. For example, carbon and oxygen form both carbon dioxide (CO) and carbon dioxide (CO2)

Benjamin Franklin

electricity, coined battery (positive, neg charge)

William Crookes

made the cathode ray tubes, discovery of the element thallium and fundamental in the development of atomic physics

J.J. Thomson

through his experiments with cathode rays, charge to mass ratio of an electron, plum pudding model

Robert Millikan

charge and mass of an electron, oil drop experiment

Eugen Goldstein

discovered canal rays (positive ions) (found proton's charge, but not the actual proton)

William Roentgen

discovered X-rays in 1895 while experimenting with cathode rays, experiemented w/ uranium

Antoine Becquerel

BIG RADIATION GUY (uranium), discovering spontaneous radioactivity, uranium compound could expose a photographic plate through black paper, even in the dark. This led to his conclusion that the material was emitting its own radiation spontaneously.

Ernest Rutherford

OVERSAW gold foil experiment, alpha beta gamma radiation, (his model is also known at nuclear model)

James Chadwick

discovering the neutron in 1932

Henry Moseley

the atomic number is the correct basis for the periodic table, rather than atomic mass

Johann Balmer

discovering a formula in 1885 that accurately predicts the wavelengths of the spectral lines of hydrogen, known as the ______ series

Max Planck

the father of quantum theory, which he developed in 1900 by proposing that energy is emitted and absorbed in discrete packets called "quanta", _____'s constant

Neils Bohr

planetary model/develped the ___ model of the atom/electrons exist in specific, fixed orbits around the nucleus and jump between these orbits, releasing or absorbing energy as light

Albert Einstein

PHOTOELECTRIC EFFECT (light is a particle, electrons jump energy levels), developing the theory of relativity, which revolutionized the understanding of space, time, and gravity

Louis DeBroglie

wave-particle duality, all matter exhibits both wave and particle properties.

Werner Heisenberg

uncertainty principle: that there are inherent limits to the precision with which certain pairs of physical properties, such as a particle's position and momentum, can be simultaneously known

Erwin Schrodinger

______ equation: In 1926, he developed a differential equation that provides a mathematical model for the wave-like behavior of electrons and other particles
Wave function: The equation uses a mathematical function called the wave function, represented by the Greek letter psi (Ψcap psiΨ), to describe the probability of finding a particle in a specific location.