Matter & Its Changes

1. a substance containing atoms of two or more different elements chemically bonded together.
5. law that states that the total mass of the reactants before a chemical reaction is the same as the total mass of the products after the chemical reaction.
6. a starting substance in a chemical reaction.
10. two or more atoms that are held together by covalent bonds and act as a unit.
11. a process in which atoms of one or more substances rearrange to form one or more new substances.
15. the change in state from a liquid to a gas.
16. the transfer of thermal energy from a region of higher temperature to a region of lower temperature.
18. a characteristic of matter that can be observed or measured without changing the identity of the matter.
21. matter with a composition that is always the same.
22. an increase in a material's volume when the temperature is increased.
23. a number placed in front of an element symbol or chemical formula in an equation.
27. a decrease in a material's volume when the temperature is decreased.
28. a small particle that is the building block of matter.
29. energy due to motion.
31. occurs when a substance reacts with another substance, changing it into a new substance.
32. the result of the motion of all the particles, and the distance and attractions between those particles in the system.
33. a characteristic of matter that can be observed as it changes to a different type of matter.

2. the amount of force per unit area applied to an object's surface.
3. a change in matter in which the substances that make up the matter change into other substances with different chemical and physical properties.
4. the ability of a type of matter to burn easily.
7. more energy is required to break the bonds of the reactants than is released when products form.
8. occurs when substances react with oxidizing agents, changing it to a new substance.
9. more energy is released when the products form than is required to break the bonds in the reactants.
12. law that states that energy is always transferring, but energy is not created or destroyed.
13. the energy released when atoms form bonds.
14. the amount of matter in an object.
17. the mass per unit volume of a substance.
19. stored energy due to the interactions between objects or particles.
20. the measure of the average kinetic energy of the particles in a material.
24. a group of chemical symbols and numbers that represent the elements and the number of atoms of each element that make up a compound.
25. the amount of space a substance takes up.
26. a substance produced by a chemical reaction.
30. a substance that consists of only one type of atom.