Bridging Course 1 Flashcards
postulated that all matter is made up of small indestructive units called atoms
Democritus
proposed his atomic theory.
1. Each element is made up of atoms.
2. Atoms of a given element are identical.
3. Compounds are formed when atoms
Shal combine with each other.
4. Chemical reactions involve
reorganization of the atoms.
John Dalton
created the periodic table and discovered that the properties of elements were periodic functions of their atomic weights
Dmitri Mendeleev
proposed the theory of electromagnetism and made the connection between light and electromagnetic waves.
James Clerk Maxwell
proposed that electricity was made of discrete negative particles called electrons
George Stoney
made experiments with cathode ray tubes demonstrating that cathode rays have a negative charge
Sir William Crooke
used cathode ray tubes to study canal rays which had electrical and magnetic properties opposite of an electron
Eugene Goldstein
discovered that certain chemicals glowed when exposed to cathode rays. He named these X-rays.
Wilhelm Roentgen
discovered radiation by studying the effects of X-rays on photographic film
Henri Becquerel
used cathode ray tubes to determine the charge to mass ratio of an electron
Sir Joseph John Thomson
discovered alpha, beta, and gamma rays in radiation.
Ernest Rutherford
theorized that radioactive particles cause atoms to break down releasing radiation that takes the form of energy and subatomic particles. They discovered the radioactive elements polonium and radium
Pierre and Marie Curie
proposed the idea of quantization to explain how a hot, glowing object emitted light.
Max Planck
discovered that there appeared to be more than one element at each position on the periodic table. The term isotope was coined by ______________ as a suitable name for these elements.
Frederick Soddy; Margaret Todd
found that noble gases have stable electron configurations
Richard Abegg
created the theories of relativity and hypothesized about the particle nature of light.
Albert Einstein
invented a device that could detect alpha particles
Hans Geiger
determined the charge of an electron through his oil drop experiment
Robert Millikan
performed the alpha particle experiment and established that the nucleus was very dense, very small, and positively charged.
Ernest Rutherford
discovered that the number of protons in an element determines its atomic number.
Henry Moseley
developed the Bohr atomic model, with electrons travelling in orbits around the nucleus.
Neils Bohr
proposed that electrons have a wave-particle duality.
Louis de Broglie
developed the Schrodinger equation which describes how the quantum state of a system changes with time.
Erwin Schrodinger
atomic model proposed by John Dalton
Dalton’s Billiard Ball Model
