Thomson the British Chemist
Born: December 18,1856 Died: August 30,1940
J.J. Thomson was a lecturer, physicist, & laureate. He spent most of his life discovering the existence of electrons & isotopes. Plus he concluded a idea on a process that measures the properties of atomic masses.He discovered electrons by experimenting with electric currents inside an empty glass tube. The electric current would pass from the cathode(negative electrode) to the anode(positive electrode). As he began experimenting, Thomson realized that the rays that were being created were negatively charged, since the glow would occur in the positive end.Thomson, thus, concluded that those particles were incredibly light, negatively charged, & were the building blocks of an atom. Thomson discovered isotopes by testing canal rays.He channeled ionized neon through a magnetic and electric field. The results were that the rays deflected in to different parabolas, indicating that neon has two atoms with different masses,neon-20 & neon-22.
Thomson's Atomic Strucure Theory:
-Atoms are a sphere with a positive charge distributed evenly through the atom containing negatively charged electrons separately embedded into the atom.
-Atoms as a whole are nuetrally charged because the amount of positive charge in it cancels out the amount of negatively charged electrons.-The electrons can be moved around or taken out of the atom, the positive charge can not.
Thomson's theories & experiments have shown defect in Dalton's theory & have made Chemistry more precise, he conclusions & experiments have lead to the invention of the mass spectrometer with the help of Francis William Aston.
