Across
- 3. the science that employs the scientific method to study living things
- 4. cells that do not contain nuclei
- 6. cells that contain nuclei
- 7. a substance that speeds up the rate of a chemical reaction
- 8. an attraction between molecules of the same substance.
- 9. the process of gathering information about events or processes in a careful, orderly way.
- 10. variable that is deliberately changed
- 11. strong forces bind protons and neutrons together to form the ______
- 12. an organized way of using evidence to learn about the natural
- 13. devices that produce magnified images of structures that are too small to see with the unaided eye
- 14. forms when electrons are shared between atoms
- 17. a pure substance that consists entirely of one type of atom
- 18. atoms of the same element that differ in the number of neutrons they contain.
- 21. a slight attraction can develop between the oppositely charged regions of nearby molecules.
- 22. system a decimal system of measurements whose units are based on certain physical standards and are scaled on certain physical standards and are scaled on multiples of 10.
- 23. smallest unit of most compounds
- 25. proteins that act as biological catalysts.
Down
- 1. small particles of RNA and protein found throughout the cytoplasm
- 2. positively and negatively charged atoms
- 5. variable that is observed and that changes in response to the manipulated variable is called _______
- 6. the site where lipid components of the cell membrane are assembled, along with proteins and other materials that are exported from the cell
- 15. portion of the cell outside the nucleus
- 16. proposed scientific explanation for a set of observations
- 19. cell is able to reproduce so that a group of cells.
- 20. a substance formed by the chemical combination of two or more elements in definite proportions.
- 24. Bond/ formed when one or more electrons are transferred from one atom to another.