40 points if you answer! a neutral atom has an atomic number of 20 and a mass number of 42. how many electrons does the atom have? question 4 options: 20 22 42 62

Acoal-fired plant generates 600 mw of electric power. the plant uses 4.8 x 10^6 kg of coal each day, and the heat of combustion of coal is 3.3x 10^7 j/kg. the steam that drives the turbines is at a temperature of 300° c, and the exhaust water is at 37° c. (a) what is the overall efficiency of the plant for generating electric power? (b) how much thermal energy is exhausted each day? (c) what is the change in entropy of the universe for this heat engine? (d) using the same heat reservoirs, what is the maximum possible (carnot) efficiency for a heat engine?

The most important difference between a wedge and an inclined plane is a. their size b. their shape c. how they are used d. what they are made of

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