Chemistry Crossword

5. Pure substance formed when at least one metal and one non-metal combine.
6. The smallest part of an element that is representative of that element; a neutral particle made up of a nucleus containing protons and neutrons, and in which the number of electrons equals the number of protons.
7. Group 18 elements in the periodic table; the most stable and unreactive elements.
8. New substance produced in a chemical reaction between reactants.
10. Chemical reaction that absorbs energy; example cold pack.
13. Pure substance formed when non-metals combine.
14. A pure substance that cannot be broken down into other substances; the substance is made up of only one type of atom.
15. Metals Group 2 elements in the periodic table; their reactivity is not as strong as that of the alkali metals.
16. Number of protons in the nucleus of one atom of an element.
23. Group of atoms acting as one (for example, carbonate or CO32-).

1. Principle that matter is not created or destroyed in a chemical reaction; the mass of the products always equals the mass of the reactants.
2. Substance that helps a chemical reaction to proceed more quickly.
3. Description of a solid that can be stretched into a long wire.
4. Change that results when two or more substances react to create a different substance or substances and the new substances have completely different properties from the original ones.
9. Change in the appearance or state of a substance that does not change the composition.
10. Chemical reaction that releases energy; example fire.
11. A reaction that takes place when two or more substances react to form new substances.
12. Mass of one atom of an element calculated from the total number of protons, neutrons, and electrons of that atom; measured in amu.
13. Anything that has mass and occupies space.
17. Description of a substance that can be pounded or rolled into sheets.
18. Ability of a substance to conduct electricity or heat.
19. Substance that reacts with another substance or substances in a chemical reaction to create new substances with different properties.
20. Group 1 elements in the periodic table, not including hydrogen; the most reactive of the metals.
21. Group 17 elements in the periodic table; the most reactive non-metals.
22. Atom that has become electrically charged because it has lost or gained electrons.