Across
- 3. Elements in the same group or column have the same number of electrons present in energy levels within the outer shell of the electron cloud
- 6. Metals Less reactive, contain more valence electrons in outer energy levels.
- 7. is a change of a substance from one form to another without undergoing a change in composition
- 8. Metals Contain 2 valence electrons in outer energy levels
- 10. If an atom gains electrons it becomes negative and is called
Down
- 1. Elements with one valence electron that are very chemically reactive.
- 2. is an observable and measurable physical characteristic of matter
- 4. If an atom loses electrons it becomes positive and are called
- 5. is when one substance combines with another substance to make something completely new with different properties.
- 9. are atoms that have a positive or negative charge because they have an unequal number of protons and electrons