Across
- 5. a bond formed when charged atoms get near each other and form a bond
- 7. a form of reproduction in which cloned cells are made
- 11. a group of the same organisms living in an area at the same time
- 12. no charge, nucleus
- 14. cells that lack a nucleus
- 15. substances on the left
- 17. bond formed in polar molecules when hydrogens are attracted to nearby negative atoms
- 18. substances on the right
Down
- 1. a measure of life on earth
- 2. cells that contain a nucleus
- 3. a chemical bond formed when electrons are shared
- 4. substances made of more than two elements
- 6. has mass and takes up space
- 8. the region of earth containing life
- 9. plants and algae cells
- 10. an important compound filled with hydrogen bonds
- 13. a collection of cells performing a function
- 15. positive charge nucleus
- 16. six elements of life
- 19. negative charge around the nucleus