Answer:
Chemical energy is the potential of a chemical substance to undergo a chemical reaction to transform into other substances. Examples include batteries, food, gasoline, and etc. Breaking or making of chemical bonds involves energy, which may be either absorbed or evolved from a chemical system
The physical and chemical properties of metal can differ between the elements but if we try and generalize.
Physical properties are that they are hard, dense, shiny, malleable (can be bent), ductile (can be pulled into wires), a good conductor of heat and have high melting points meaning that they are solid at room temperature
Their chemical properties include being good electrical conductors, they make metallic bonds (ionic bonds with non-metals) and their atoms are arranged in a lattice. They release hydrogen when reacted with acids and are usually cations (positive ions).
Your answer would be C, "By conserving energy"! A gas can do work through something called the First Law of Thermodynamics. Heat that energy used by the gas during this "work" cannot be created or destroyed however it can be transferred and converted. This energy can only be stored during these processes, not removed. An example of this would be gas in a cylindrical object such as a piston. When the gas is heated, it expands and moves the piston upwards. When it expands, it stores that energy it gains through the heat given.
I hope this helps! (: