Answer:
The activation energy
Explanation:
The activation energy is the energy hump that lies between reactants and products. It is the energy barrier that reactants must cross before they are converted into products.
Based on the collision theory, only particles that possess the activation energy are able to collide in such a way that leads to reaction.
Collision of particles having an energy content less than the activation energy of the reaction merely leads to elastic collision between such particles.
when liquid water changes into solid ice, it increases in mass
The amount if protons is the same as the amount of electrons, so it would be 8. The charge is -2. Look at oxygen in the periodic table.
Answer: Burning changes the chemical make up of an object.
Explanation:
A chemical change can be defined as a change in the substance when it combines with other kind of substance to form a new substance. A chemical change can also occur when a substance is broken down into two or more products. These changes cannot be reversed. These changes affect the physical make up of an object. For example, burning as when an object is burned it cannot be transformed into its original form. A wood if burned can be converted into ash, water and carbon dioxide cannot regain its original form after burning so burning brings about chemical change in an object.