Please help me asap thankss EXPLAIN WHY A POLYTHENE ROD GAINS A NEGATIVE CHARGE WHEN IT IS RUBBED WITH A CLOTH

When a polythene rod is rubbed with a duster, the friction causes electrons to gain energy. Electrons gain enough energy to leave the atom and 'rub off' onto the polythene rod. The polythene rod has gained electrons, giving it a negative charge.

Explanation:

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answer: 802.3 kilo joules of energy represents 191.75 kilo calorie of energy.

explanation:

energy released during combustion of one mole methane = 802.3 kilo joules

if 1 kilo joule = 0.239006   kilo calorie

then ,802.3 kilo joule will be = 802.30.239006 kilo calorie

802.3 kilo joule = 191.75 kilo calorie

hence, the energy in kilo calorie is 191.75 kilo calorie.

5 w for 1hr = 5x60x60 joules=300x60=3000x6=18,000j as total energy conversion. efficiency of bulb needed for radiant to thermal within 18000