-
Democritus was born about 460 BCE.He was one of the first to discover atoms that are present in the atmosphere.These are about atoms that come in different forms.The scientific community knew that he was one of the first to realise atoms.
-
Proposed a mechanical universe with small solid masses in motion.
-
English chemist who stated the Atomic Theory whichstated that all matter was composed of small indivisibleparticles called atoms.
-
Studied the effect of electricity on solutions, coined term "electrolysis" as a splitting of molecules with electricity, developed laws of electrolysis. Faraday himself was not a proponent of atomism
-
Built one of the first gas discharge tubes
-
Arranged elements into 7 groups with similar properties. He discovered that the properties of elements "were periodic functions of the their atomic weights".
-
Proposed that electricity was made of discrete negative particles he called "electrons".
-
First to measure the electron. Developed theplum-pudding model of the atom. Describes the atom as aslightly positive sphere with small electrons inside.
-
Observed spontaneous disintegration of radioactive elements into variants he called "isotopes" or totally new elements, discovered "half-life", made initial calculations on energy released during decay.
-
Inferred a small, dense, positively-charged nucleus as theresult of the alpha particle scattering gold foil experiment.
-
Using x-ray tubes, determined the charges on the nuclei of most atoms. He wrote"The atomic number of an element is equal to the number of protons in the nucleus"
-
Discovered the existence of isotopes through the use of a mass spectrograph.
-
Discovered that electrons had a dual nature-similar to both particles and waves.
-
Conducted the first controlled chain reaction releasing energy from the atoms nucleus.
-
A Danish physicist who stated that electrons could onlyorbit the nucleus in succesively larger orbits around thenucleus. The outer orbits could hold more electrons.
