How much energy must be absorbed by 20.0 g of water to increase its temperature from 183 °C to 303 °C? (Cp of H2O = 4.184 J/g °C)

Why is the melting of ice a physical change ?

In a heat of an engine, if 700 j enters the system, and the piston does 400 j of work what is the final internal (thermal) energy of the system if the initial energy is 1,500 j

What is a number added in front of a formula in order to balance the equation