Science Vocab.

2. two or more different elements chemically combined
4. a substance that cannot be broken down
5. a chemical reaction that absorbs energy
7. Bond the force that holds cations and anions together
8. Bond the chemical in which two atoms share a pair of valence electrons
10. of mass Principle that the mass of an object or collection of objects never changes
14. new substance formed as a result of a chemical reaction
15. Replacement a chemical in which one element takes the place of another element in a compound

1. Reaction a chemical reaction is the process in which a substance is transformed into a new substance is transformed into a new substance
3. a chemical reaction in which a compound breaks down into two or more simpler substances
6. a chemical reaction in which two or more substances react to form a single substance
9. a substance that undergoes change is a chemical reaction
11. Reaction a process in which the structure and energy of an atomic nucleus are changed by interaction with another nucleus
12. replacement a chemical reaction in which two compounds exchange positive ions and form two new compounds
13. the force that holds atoms or ions together