Across
- 1. One of the elements that makes up NaCl
- 3. If a substance changes colour, it is a ________ change.
- 5. The powerhouse of a cell.
- 6. Body system that uses your heart and lungs.
- 7. Makes up 78% of the earth's atmosphere.
Down
- 1. Weather that is recorded over a 50 year time period.
- 2. The lower on the ph scale, the more ______ something is.
- 4. Protective layer covering the earth that's made from different gasses.