Alead mass is heated and placed in a foam cup calorimeter containing 50.0 ml of water at 18.0°c. the water reaches a temperature of 20.0°c. how much heat was released by the lead? (the specific heat capacity of water is 4.18 j/g°c and the density of water is 1.00 g/ml)

Heat gained or loss in a system can be calculated by multiplying the given mass to the specific heat capacity of the substance and the temperature difference. It is expressed as follows:

Heat = mC(T2-T1) 

When two objects are in contact, it should be that the heat lost is equal to what is gained by the other. So, the heat released by the lead is equal to the heat that is absorbed by the water. 

Heat = mC(T2-T1) = 50.0 mL (1.00 g/mL) (4.18 J/g °C) (20 °C - 18 °C) = 418 J

Carbon based or cells?