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Q.1 What is the mass of an electron :

Q.2 Who discovered proton ?
Q.3 Write down the name of the experiment from which proton
discovered.
Q.4 Write down the mass of proton.
Q.5 What is the specific charge of proton ?
Q.6 Out of three fundamental particles which is able to produced
X-Rays when striking to a metal surface ?
Q.7 Write down the name of the experiment from which electron

discovered.
Q.8 Who discovered electron ?
Q.9 What is the charge of 1 mole of electron ?
Q.10 What is the charge of proton and neutron.
Q.11 Write down the observations in gold foil experiment.
Q.12 Write down the conclusion drawn from gold foil experiment.
Q.13 Write down three postulates of Rutherford's atomic model.

Q.14 An element having atomic number 20 and Mass number
40.Calculate the number of electrons protons and neutrons in
its bivalent ion.
Q.15 Na has 11 protons, 11 electrons and 12 neutrons. Calculate its
atomic number and mass number.
Q.16 Give one example of isotones.
Q.17 What are isoelectronic species?
Q.18 Give one example of isobars.

Q.19 Define the term wavelength.
Q.20 Define the term frequency.
Q.21 Define the term wave number.
Q.22 Define the term velocity.
Q.23Write down the relationship between velocity, frequency and
wavelength.
Q.24 Write down two postulates of Planck's quantum theory.

Q.25 Out of three isotopes of hydrogen, which one is radioactive?
Q.26 Write down two limitations of Rutherford's atomic model.
Q.27 Write down two postulates of Bohr's atomic model.
Q.28 Write down the formulae to calculate energy of an electron in a
particular orbit and radius of a particular orbit.
Q.29 Write down the significance of de Broglie concept .
Q.30 State Heisenberg's uncertainty principle.
Q.31 Write down the relationship between de Broglie wavelength

and velocity of a microscopic particle.