Across
- 2. , The sum of protons and neutrons in the nucleus
- 4. , Good conductor of heat
- 8. , Animals without backbone
- 10. , Powerhouse of the cell
- 11. , Heat transfer by movement of air masses
- 12. , The amount of matter in an object
- 13. , Positive particles in an atom
- 14. , Microscopic openings in plant leaves through which gases are exchanged
Down
- 1. , Product of photosynthesis
- 3. , Regions in space with enormous gravity formed from collapsing stars
- 5. , The gravitational force Earth exerts on an object
- 6. , The building and structural unit of all matter
- 7. , Different forms of atoms of the same element with same atomic number
- 9. , Periodic changes in sea levels caused by the Moon’s gravity
- 12. , Everything that has mass and occupies space