(i)Cathode rays travel in straight lines and thus cast shadows of objects placed in their path.
(ii)Cathode rays possess material particles because they can rotate a light paddle wheel placed in their path.
(iii)They are deflected towards positive plate thus showing that theses are negatively charged particles knowns as electrons
(iv)They ionise gas through which they pass
(v)They are deflected by magnetic fields.
(vi)The nature of cathode rays is independent of the material of cathode.Hence they are common constituents of all matter
(vii)They can penetrate through thin metallic sheet
(viii)They can produce X-rays
(ix)The mass of a cathode ray particle is very-very small as compared to the mass of the atom from which it is formed

It shows that the element is inert gas and its atom has either 2 or 8 electrons in its outermost shell.This is because atoms with eight electrons in their outermost shell, except helium which has 2 electrons in outermost shell, are inert and do not take part in chemical combination.

He gave a new concept that particles at atomic level behave differently from the, macroscopic objects.He suggested that electrons could revolve in stable orbit without continuously radiating or losing energy.According to Bohr's model, an electron revolves in an orbit with well-defined energy.

Chadwick discovered neutrons.Hydrogen atom contains one proton and helium atom contains 2 protons.Therefore, it was thought the relative atomic mass of helium atom should be two.But the relative atomic mass of helium is 4.On examination of nuclei of atoms, it was discovered that nuclei of atoms contain another particle of the same mass as protons but of neutral charge.These were called neutrons.

The statement is true because:
(i) Whatever be the nature of the gas or the material of the cathode, the electrons have the same charge to mass(e/m) ratio i.e., 1.7589x10¹¹ coulomb per kg
(ii) The electrons obtained by different methods are identical.

The gas in discharged tube experiment (at low pressure and high voltage) get decomposed.Negatively charged particles are produced which travel from cathode to anode, thus facilitating the flow of current.Under other conditions, e.g., 1 atmosphere pressure, no dissociation of gas occurs and no current flows.

Bohr and Bury gave the following rules for the distribution of electrons around the nucleus.
(i)Electron ar revolving around the nucleus in different orbits or shells.hese energy shells are represented by numbers 1, 2, 3, 4 or K, L, M, N.
(ii)The maximum number of electrons in any shell cannot exceed 2n², where n is the number of that energy level.Thus for
K-shell, n=1, no. of electrons=2x1²=2
L-shell, n=2, no. of electrons=2x2²=8
M-shell, n=3, no. of electrons=2x3²=18
N-shell, n=1, no. of electrons=2x4²=32
(iii)The outermost orbit of an atom cannot have more than 8 electrons and the next to the outer shell (penultimate shell) can have at the most 18 electrons.
(iv)It is not absolutely necessary that an orbit has its full quota of electrons before starting to fill the next higher orbit but the shells are filled in a stepwise manner.