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Democritus
Democritus created the first atomic model which was a sphere with no neutrons, electrons, or protrons. It helped people understand the concept of an atom and encouraged other scientists to further look into the science of an atom. -
Antione Lavoisier
He came up with the law of conservation of masses. It states that when two chemical substances' weights combine, it is equal to the weight of the newly formed compound. -
John Dalton
His theory was that all matter was made of atoms and that atoms are indivisible and industructable. He also said that all atoms are identical in mass and properties. Lastly he came up with that compounds are formed by a combination of two or more different kinds of atoms and that a chemical reaction is an arrangement of atoms. -
Joseph Louis Proust
He discovereed the law of definite proportions. This law states that a compound regardless of how it was created, is composed of exact proportions of elements. -
Indivisible, solid sphere model
It explains how atoms combine to form molecules. It is discovered by John Dalton. -
Michael Faraday
Faraday discovered that the reason why atoms were in compounds was because of electrical forces. The electrical forces were electrodes. -
Electron cloud model
It's a model that shows that electrons move around the nucleus in a cloud of energy. -
Niels Bohr
He discovered that electrons travel in seperate orbits around the nucleus. He also found out that the propety element is determined by the amount of electrons in the outer orbit. -
Henri Becquerel
He discovered radioactivity which is the particles emitted from the nuclei. -
Pierre and Marie Curie
They discovered two important elements, radium and polonium. -
Max Planck
Planck proposed the quantrom theory which was to explain the color of glowing matters. He stated that energy is emitted every minute and discrete quantized amount of packets, rather than in an unbroken wave. -
J J Thomson
The cathode rays led to his discovery of the negative charged electrons. -
Otto Hahn
He discovered a radioactive isotope of thorium called radioacinium. He also discovered nuclear fission which was the primary chemical process in nuclear reaction. -
Albert Einstein
Proposed the idea that light exists as little particles called protons. He also came up with a new way of counting and determining the size of atoms in a given space. -
Planetary Model
This model states that the nucleus is positive and that there are negatively charged electrons outside the nucleus. -
Plum Pudding Model
Discovered by J.J Thomson, the model showed that atoms have negative charged electrons in a postive charged substrate. -
Robert Milikan
His oil drop experiment allowed him to find the unit charge of an electon. Then he found the calculation mass of the electon. -
Ernst Rutherford
Proposed the nucleus and that all electrons were in the occupied space around it. -
Quantum Mechanical Model
Shows that electrons are found in regions called orbitals around the nucleus. -
Louis de Brogile
He discovered the wave nature of electrons. He proposed that particles can behave like waves. -
Erwin Schrondinger
Discovered the quantram mechanical model which predicts the location of the electron. This is also known as the necleus surrounded by an electron cloud. The propability of fiding an election greatest is where the cloud is most dense. -
James Chadwick
He discovered the neutron. The neutron is a particle that has no charge and it is a part of the nucleus. -
Lisa Meitner
Her invention was to emmit neutrons to make them clash into the atom. This is what led to the discovery of the fission. -
Glenn T. Seaborg
He helped discover plutonium and all transuranium elements through element 102. He also identified more than 100 isotopes of elements on the Periodic Table. -
Aristotle
He did not belive in atoms. He thought matter was made of four elements, earth, fire, water, and air.
