Across
- 2. A colorless, odorless, tasteless nonflammable gas 21% of atmosphere.
- 4. The ability of an element to chemically react with another.
- 6. This is necessary for photosynthesis
- 10. Cells that do contain nucleus
- 12. Organisms that make their own food through photosynthesis
- 13. The amount of mass in a given volume.
- 14. The ability to reflect light off a surface(shiny)
- 15. Hardest natural substance on earth
Down
- 1. A substance that cannot be broken into simpler substance
- 3. Control-centre of a cell,DNA is stored here.
- 5. Speed travel in certain direction.
- 7. Two or more elements chemically combined
- 8. Alloy of copper and zinc .
- 9. A gas molecule that consists of three oxygen atoms
- 11. A force that resists the motion between two surfaces in contact