What step is the fossil fuels are burned the thermal energy if the burning fuel turns water into steam

Acamcorder has a power rating of 17 watts. if the output voltage from its battery is 7 volts, what current does it use?units:

The kw for water at 0 °c is 0.12× 10–14 m2. calculate the ph of a neutral aqueous solution at 0 °c.

110 g of water (specific heat = 4.184 j/g c) and 100 g of a metal sample (specific heat = 0.397 j/g c) are heated from 25 degrees c to 75 degrees c. which substance required more thermal energy?