Phase Matter with uniform properties and a fixed composition is called a phase. Types of Phase System There are two types of phase. (i) Homogeneous Phase System (Single Phase System) Water at normal pressure and at room temperature exists as a single liquid phase, i.e. all the properties of water are uniform throughout this liquid…
Millikan, in 1909, determined the charge on electron by the apparatus consisting of a metallic chamber having two parts. The chamber is filled with air whose pressure can be adjusted by a vacuum pump. There are two electrodes A and A’. These electrodes are used to generate an electrical field in the space between the…
i) In order to measure the e/m value of electrons J.J Thomson in 1897 devised an instrument consisting of a discharge tube. ii) The cathode rays are allowed to pass through electric and magnetic fields. iii) When both the fields are off, the beam of cathode rays consisting of electrons produce bright luminous spot at…
The protons and electrons were discovered in 1886 and their properties were completely determined till 1895. Rutherford predicted in 1920 that some kind of neutral particles having mass equal to proton must be present in an atom. Chadwick discovered neutron in 1932 and was awarded Nobel Prize in Physics in 1935. EXPERIMENT A stream of…
As the atom was considered neutral, therefore, soon after the discovery of negatively charged particles i.e., electrons, scientists tried to discover a positively charged constituent of atom. In 1886, Eugene Goldstein used a discharge tube with perforated cathode. He observed a glow in the region behind the cathode. This glow was consequence of rays, which…
To study the properties of cathode rays systematic investigations were made by W. Crooks, J.J. Thomson and J. Perrin. They established the following properties of cathode rays: Cathode rays are negatively charged. In 1895, J.Perrin showed that cathode rays are deflected in a magnetic field perpendicular to the line joining the two poles. In 1897,…