science crossword

4. Zn in the periodic table
8. Al in the periodic table
10. S in the periodic table
12. anything that occupies space and has mass
15. process in which molecules move from an area of higher consintration to an area with lower consintration
16. invisible negitivaly charged particle that orbits the nucleous of an atom
17. O in the periodic table
18. change that results in two or more substances react to create a new substance
20. a substance that helps a chemical act more quickly
22. a part of a chemical reaction
24. orbit of electrons around the nuculous of an atom

1. Ca in the periodic table
2. ll, brittle element that does not conduct electricity
3. He in the periodic table
5. a change in state or appearance
6. mixing a substance with air or water to make the substance less consintrated
7. mass in one atom of an element
9. NOx(g); major air pollutant; forms when nitrogen combines with oxygen as a result of fuel combustion; gives smog its characteristic brown colour; major source: motor vehicles
11. a system in which nothing can enter and nothing can leave
13. Fe in the periodic table
14. a new substance formed in some kind of reaction
19. shiny, malleable, ductile element that conducts electricity
21. element that has both metallic and non-metallic properties
23. another word or poisonous
25. H in the periodic table