Loggers cut down 2 identical trees. one tree was cut down with a hand saw and one was cut down with an electric saw. which activity involved more work?

If 21.2 kcals of energy is released by this reaction, how many kj does the reaction release? (1 cal 4.184 j)

Africtionless piston-cylinder contains 50 l of saturated liquid r-134a. the piston has a mass and an area resulting in an applied pressure of 500 kpa on the refrigerant. the refrigerant is now heated until its temperature rises to 70∘c. calculate the work (in kj) done during this process.

Because atoms of elements in the same group of thbecause atoms of elements in the same group of the periodic table have the same number of neutrons, they have similar properties. select the best answer from the choices provided t fe periodic table have the same number of neutrons, they have similar properties. select the best answer from the choices provided t f