You don't "turn" it into energy; petroleum HAS stored energy (chemical energy).However, you can turn it into ANOTHER TYPE OF ENERGY; usually this is done by burning the petroleum, and using it to drive machinery.
Since burning fuels is wasteful (the efficiency is limited, in theory, to the Carnot efficiency of a heat engine), other options are being explored, such as chemical reactions in a fuel cell. But such technology is not yet used on a large scale.
Answer:
As water freezes, a crystalline structure preserved by hydrogen bonding is formed by water molecules. Less dense than liquid water is solid water, or ice. Ice is less dense than water since molecules are pulled farther apart by the direction of hydrogen bonds, which decreases density.
Explanation:
Ions have an extra or lost an electron. Isotopes have different numbers of neutrons.