Chemistry Crossword

5. neutral particle in the nucleus of an atom
7. element that has both metallic and non-metallic properties
8. catalyst involved in chemical reactions in living things
11. cloudy mixture in which tiny particles of one substance are held within another, and the particles can be separated out
13. Chemical reaction that occurs when oxygen reacts with a substance to form a new substance and give off energy
15. chemical reaction that absorbs energy
17. pure substance formed when non-metals combine
18. a table in which the elements are organized by their physical and chemical properties
19. pure substance formed when at least one metal and one non-metal combine
21. substance made of only one kind of matter, which has a unique set of properties
22. Change that results when two or more substances react to create a different substance or substances
23. an experiment in which one or more products of a chemical reaction can escape
24. substance that reacts with another substance or substances in a chemical reaction to create new substances with different properties

1. group 18 elements in the periodic table;the most stable and unreactive elements
2. group 17 elements in the periodic table;the most reactive non-metals
3. cloudy mixture in which tiny particles of one substance are held within another and particles cannot be separated out from the other substance
4. positively charged particle in the nucleus of an atom
6. vertical column of elements in the periodic table
9. heterogeneous mixture;mixture in which the different substances that make up the mixture are visible
10. change in the appearance or state of a substance that does not change the composition
12. chemical reaction that releases energy
14. combination of pure substances
16. substance that strongly resists the flow of electricity
20. description of a substance that can be pounded or rolled into sheets
25. substance that helps a chemical reaction to proceed more quickly