Explain how the temperature of a substance is
related to the kinetic energy of its molecules.

Temperature is directly proportional to the Kinetic Energy of molecules.

Explanation: When a certain substance is heated its molecules absorbs heat or thermal energy. Upon the absorption of heat the molecules tend to move faster since it gains energy, so its kinetic energy increases as well. An increase in temperature will result to an increase in the Kinetic energy on the molecules.

2h2o2--> 2h2o + o2

this reaction is of the spontaneous decomposition of hydrogen peroxide down into water and oxygen.

add 2 molecules of hydrogen peroxide and 2 molecules of water. since oxygen is naturally diatomic, the total number of atoms of each element is now the same on both sides of the equation so it is balanced.

this may not be entirely correct but let me know.