Across
- 2. a change of materials into another, new materials with different properties and one or more than one new substances are formed
- 6. more energy is absorbed when the bonds in the reactants are broken than is released when new bonds are formed in the products
- 7. the smallest unit of matter that is composed of three sub-atomic particles: the proton, the neutron, and the electron
- 8. a chemical reaction that releases energy by light or heat
- 9. the attraction between two or more atoms that allows them to be able to form a stable chemical compound
- 10. a pure substance which consists of identical atoms or molecules with only one core of an atom
Down
- 1. the electrons in an atom's outermost electron shell
- 3. a group of two or more atoms held together by attractive forces known as chemical bonds
- 4. arranges the chemical elements into rows and columns
- 5. tells us the number of atoms of each element in a compound