Matter and changes

6. A small particle that is the building block of matter.
9. Matter with a composition that is always the same.
11. Two or more atoms that are held together by covalent bonds and act as a unit.
12. A staring substance in a chemical reaction/
13. A process in which atoms of one or more substances rearrange to form one or more new substances.
15. 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.
16. A change in matter in which the substances that make up the matter change into other substances with different chemical and physical properties.

1. More energy is required to break bonds of the reactants than is released when products form.
2. A substance that consists of only one kind of atom.
3. Law that states that energy is always transferring, but energy is not created or destroyed.
4. A substance produced by a chemical reaction.
5. The energy released when atoms form bonds.
7. A characteristic of matter that can be observed or measured without changing the identity of the matter.
8. more energy is released when products form than is required to break bonds in the reactants.
10. A characteristic of matter that can be observed as it changes to a different type of matter.
13. A substance containing atoms of two or more different elements chemically bonded together.
14. A number placed in front of an element symbol or chemical formula in an equation.
17. A group of chemical symbols and numbers that represent the elements and the numbers of atoms of each element that make up a compound.