LEUCIPUS AND DEMOCRITUS
Understanding Atom By Expert. According to Leucippus and Democritus, the notion of an atom is the smallest part of a material that cannot be further divided into certain parts. Atoms are the constituent of all matter in the world.
Understanding Atom By Expert. According to John Dalton, the meaning of an atom is the smallest particle rather than a substance that cannot be broken down into smaller particles through ordinary chemical reactions.
JOSEPH JOHN THOMPSON
According to Joseph John Thompson, the meaning of an atom is a ball that is positively charged and surrounded by electrons which are like raisin bread.
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According to Ernest Rutherford, the definition of an atom is a particle consisting of protons and neutrons and is surrounded by electrons.
There is an emphasis that must be understood by everyone that took cannot be further divided and means that atoms that can be divided again, such as oxygen atoms that are split into basic particles of neutrons, protons, and electrons are not an atom anymore, but have become an ion.
THE HISTORY OF THE INVENTION OF ATOM
Then several studies support the theory of atoms put forward by John Dalton. Like Micheal Faraday also discovered the theory of molecular solving using electrolysis in 1832 and J. Plucker who invented the cathode tube in 1839.
And then followed by Dmitri Mendeleev’s discovery of the periodic law in 1869, then named John C. Maxwell in 1873 who carried out experimental research which found that an electron has a certain mass through an experiment shooting into cathode rays.
Atomic theories always undergo development from time to time according to discoveries made by experts. The theory of the atom dates back to the BC century. A philosopher from Greece named Democritus argues that a matter is discontinuous.
Dalton’s Atomic Theory
A very simple atomic model is the Dalton atomic model. Dalton’s model of the atom is a solid sphere that has no charge.
The law of conservation of mass Lavoisier says (that the total mass of substances before reacting is equal to the total mass of substances resulting from the reaction). Likewise, with the law of fixed order, the law of sprouts says (that the mass ratio of the elements in a compound is always constant).
John Dalton’s atomic theory raises one weakness, which is that it cannot explain how matter can conduct electricity. How could a solid ball conduct electricity, because electricity conducts moving electrons.