Define the following terms:

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 (I) Ionization potential : It is the energy needed to remove an electron from an isolated atom.

(II) Covalent bonding: It is a force holding atoms of two non-metals together which share a pair of electron.

(III) Doping: process of adding impurities to intrinsic semiconductor to increase conducting properties.

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An electrostatic CRT has parallel deflection plates 1.5 cm long and 6mm apart. The screen is 55cm from the centre of the deflecting plates. The deflecting and accelerating potentials are 150 V and 2.5 kilovolts respectively. Determine the:

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