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The alchemists contributed to the atom by introducing that they thought matter could be eternal, and no matter could come from nothing. They thought material things are made from particles that are very small, and particles are always moving. -
He thought atoms themselves are indivisible, and atoms join together to create things. -
He thought atoms were uniform, solid, hard, incompressible, and indestructible. He thought they moved in infinite numbers through infinite space until stopped. -
This model introduced that the sun is the center of the universe and the planets move around it. Ernest Rutherford said that an atom is like this, with the nucleus in the center and the electrons around it. -
He demonstrated matter is made up of tiny particles. He also discovered the relationship between pressure and volume in a gas. -
He said an element is a substance that cant be decomposed into another one. -
He thought that matter is made up of atoms that are indivisible. He thought all atoms of the same element are identical and different atoms cant be created or destroyed. -
This model defined the atom to be a ball like structure. -
He said volume of gas at the same amount and temperature contain the same amount of molecules. -
He built a systemic table of all 70 elements known. -
He discovered all atoms contain tiny negatively charged subatomic particles or electrons. -
They discovered radioactivity between elements, and they discovered radium. -
JJ Thompson made a model where all the electrons were embedded in a uniform sphere of positive charge. -
He mathematically predicted the size of both atoms and molecules. He did this by the movement of molecules in a liquid caused by the Brownian motion. -
He described the atoms as having a tiny dense and positive charged nucleus. He said the electrons revolve around the nucleus like planets around the sun. -
He made an atomic structure model, but they failed to explain the Zeeman effects and the Stark effect. -
He discovered each elements x-rays at a unique frequency. -
He discovered electrons are tiny negatively charged subatomic particles in all atoms. -
With this model, scientists could now make educated guesses with the position of the electrons. -
He discovered the neutron and he measured the neutrons mass.