Before there is a transfer of charges between objects, they are uncharged. What does this mean? (pls answer by 7:35)

When many atoms are split in a chain reaction, a large explosion occurs. this is an example of what type of energy conservation

How many neutrons does element x if it’s atomic number is 28 and its mass number is 87

Two kilograms of air within a piston–cylinder assembly executes a carnot power cycle with maximum and minimum temperatures of 800 k and 300 k, respectively. the heat transfer to the air during the isothermal expansion is 60 kj. at the end of the isothermal expansion the volume is 0.4 m3. assume the ideal gas model for the air. determine the thermal efficiency, the volume at the beginning of the isothermal expansion, in m3, and the work during the adiabatic expansion, in kj.