Atomic theory

By taden
  • Dalton

    Dalton discovered that oxygen combined with either one or two volumes of nitric oxide in closed vessels over water and this pioneering observation of integral multiple proportions provided
    important experimental evidence for his incipient atomic ideas. experiments on gases led to his discovery that the total pressure of a mixture of gases amounted to the sum of the partial pressures that each individual gas exerted while occupying the same space.
  • thomson

    suggested a model of the atom as a sphere of positive matter in which electrons are positioned by electrostatic forces.According to this experiment, he concluded that the atom does not contain any space and it has a positively charged nucleus. . He discovered the electrons are encircling by a volume of positive charge and negatively charged.
  • Rutherford

    that the atom is mostly empty space, with nearly all of its mass concentrated in a tiny central nucleus. The nucleus is positively charged and surrounded at a great distance by the negatively charged electrons. There is a concentration of positive charge in the atom. Like charges repel, so the positive alpha particles were being repelled by positive charges.
  • Bohr

    Bohr's theory, which was named quantum theory, proposed that electrons circle the nucleus following the classical laws but subject to limitations, such as the orbits they can occupy and the energy they lose as radiation when they jump from one orbit to another He concluded that electron will have more energy if it is located away from the nucleus whereas the electrons will have less energy if it located near the nucleus.