Answer:

Explanation:
Hello!
In this case, when we want to balance chemical reactions such as in this case, the idea is to equal to number of atoms of each element at each side of the equation according to the lay of conservation of mass, just as shown below:

Because we have four phosphorous and ten oxygen atoms at each side.
Best regards!
Gravity is a force which tries to pull two objects toward each other. Anything which has mass also has a gravitational pull. The more massive an object is, the stronger its gravitational pull is. Earth's gravity is what keeps you on the ground and what causes objects to fall.
Answer:
Mass, temperature, and phase.
I think temperature because the higher the temperature of a given quantity of a substance, more is its thermal energy. Similarly, for the same temperature, higher mass of a substance will contain more thermal energy.
B. Copper since the rest of the choices are compounds. Copper is an element.