cross word

3. catalyst involved in chemical reactions in living things
4. description of a solid that can be stretched into a long wire
8. dull, brittle element that does not conduct electricity
11. pure substance formed when two non-metals combine
14. horizontal row of elements in the periodic table
16. a reaction that takes place when two or more substances react to form new substance
20. new substance produced in a chemical reaction between reactants
21. invisible negatively charged particle that orbits the nucleus of an atom
22. energy stored in chemical and released when chemicals react; a form of potential or stored energy
23. element that has both metallic and non-metallic properties
24. pure substance that cannot be broken down into other substances

1. substance that reacts with another substance or substances in a chemical reaction
2. group 17 elements in the periodic table; the most reactive non-metals
5. atom that has become electrically charged because it has lost or gained electrons
6. description of a substance that can be pounded or rolled into sheets
7. colourless, odourless gas; produced by incomplete combustion of chemicals containing carbon
9. the sum of the number of protons and neutrons in an atom
10. group 2 elements in the periodic table
11. shiny, malleable, ductile element that conducts electricity
12. a table in which the elements are organized by their physical and chemical properties
13. group 18 elements in the periodic table; the most stable an unreactive elements
15. or substances
16. change that results when two or more substances react to create a different
17. number of protons in the nucleus of one atom of an element
18. pure substance formed when at least one metal and one non-metal
19. group 1 elements in the periodic table, not including hydrogen