LS - Crossword Labs

1. a attraction between different substances
3. an organized way of using evidence to learn about the natural world
6. these carry no charge
8. a solution that has a higher concentration of hydrogen ions than pure water and pH values below 7
10. a bond that is formed by the sharing of electrons between two atoms
11. an attraction between molecules of the same substance
14. a solution that has lower concentrations of hydrogen ions than pure water and pH values above 7
15. a substance formed by the combination of two or more elements
17. the center of the atom
20. factors that can change in an experiment are known as
23. the elements or compounds that enter into a chemical reaction
25. If an atom gains or loses a neutron, they become this
27. simple sugar molecules
29. all living things are made up of these
30. a substance composed of two or more elements or compounds that are mixed together but not chemically combined.

2. a disproved hypothesis that stated that life could arise from nonliving matter
4. a bond that is formed by the transfer of one or more electrons from one atom to another
5. long-chain carbohydrates
7. a possible explanation for a set of observations or an answer to a scientific question
9. The smallest unit of most chemical compounds
12. a decimal system based on standards and is scaled on multiples of 10.
13. the energy needed to get a reaction going
16. a well-tested explanation that unifies a broad range of observations.
18. the combination of chemical changes in which an organism builds up or breaks down materials as it carries out its life processes
19. the substances formed by a chemical reaction
21. compounds that prevent sharp swings of pH in living things
22. these made up of protons, neutrons and electrons
24. positively charged particles
26. biological catalysts that speed up virtually every important chemical reaction that takes place in the cells
28. negatively charged particles