Matthew is looking at two different atoms. one has 8 protons and 10 neutrons. the other substance has 8 protons and 12 neutrons. are these the same element? why or why not?

We put a force of 50n on an object and the acceleration is 100 m/s². what is the mass of the object?

Air is contained in a variable-load piston-cylinder device equipped with a paddle wheel. initially, air is at 400 kpa and 17°c. the paddle wheel is now turned by an external electric motor until 75 kj/kg of work has been transferred to air. during this process, heat is transferred to maintain a constant air temperature while allowing the gas volume to triple. calculate the required amount of heat transfer in kj/kg.

Which of these has some mechanical energy? a. an atom b. heat inside earth c. a book on a shelf d. the fire from a lit match