Ch 5 Chemistry Class 11 Notes

• Name the fundamental particles of atom.
• How Electrons were Discovered? A gas discharge tube is fitted with two metallic electrodes acting as cathode and anode. The tube is filled with a gas, air or vapours of a substance at any desired pressure. The electrodes are connected to a source of high voltage. The tube is attached to a vacuum pump by means of a small side tube so that the conduction of electricity may be studied at any value of low pressure
• How was it proved that cathode rays are negatively charged particles? OR How the bending of the cathode rays in the electric and magnetic field prove that they are negatively charged?
• What type of fluorescence is shown by cathode rays?
• Which observations prove that cathode rays cast shadow?
• Which observations prove that cathode rays have momentum? Or Prove that cathode rays have momentum.
• Why is it necessary to decrease the pressure in the discharge tube to get the cathode rays?
• Whichever gas is used in the discharge tube the nature of the cathode rays remains the same. Why?
• Why e/m value of the cathode rays is just equal to that of electron?
• Why the positive rays are also called canal rays? Give reason.
• What is the reason for the production of positive rays?
• The e/m values of positive rays for different gases are different, but those for cathode rays the e/m values are same. Justify it. 
• The e/m value of positive rays obtained from the hydrogen gas is 1836 timesless than that of cathode rays. Justify it.
• Which particles are formed by the decay of free neutron?
• How the slow neutrons prove to be more effective than fast neutrons? 
• Give properties of Neutron. 
• How did Rutherford’s model of an atom proved the existence of nucleus of the atom?
• What are the defects of Rutherford’s model of atom?
• What does Planck’s quantum theory say? Mention main points.
• How the energy of the photon can be calculated from the measurement of the frequency, wavelength or wave number of the photon?
• How do you justify that the distances between adjacent orbits of Hydrogen atom go on increasing from lower to the higher orbits? 
• How do you prove that the energy associated with the electron which is revolving around the nucleus of H-atom is negative?
• How do you come to know that the velocities of electrons in higher orbits are less than those in lower orbits of hydrogen atom?
• Energy of an electron is inversely proportional to ‘n2 ’ but energy of higher orbits is always greater than those of the lower orbits. Why?
• The energy difference between adjacent levels goes on decreasing sharply. Why?
• What are the features/characteristics of line spectrum?
• What is atomic emission spectrum?
• Detail out the work of Moseley on X-rays.
• What is meant by dual particle nature of matter?
• Prove that microscopic bodies can have waves in measurable range.
• What is line spectrum of hydrogen and how it differs from continuous spectrum?
• How Bohr’s model justifies the H-spectra?
• Heisenberg’s uncertainty principle has no relation with Bohr’s atomic model. Justify it. 
• How Compton Effect helps to study uncertainty principle?
• Define quantum numbers. 
• What is the function of principal quantum number?
• What is the function of azimuthal quantum number?
• The magnetic quantum number gives orientation of orbital in space. Justify it.
• State Pauli's Exclusion Principle.
• What is the function of spin quantum number?
• Calculate mass of an electron when e/m=1.7588x1011CKg-1 OR Calculate mass of an electron from its e/m value.
• How does the Bohr’s model justify the Moseley’s equation?
• Draw the shapes of s, p and d sub-shells.