Across
- 3. pure substance that cannot be broken down into other substances; substance made up of only one type of atom
- 8. shiny, malleable, ductile element that conducts electricity
- 10. group 1 elements in the periodic table, not including hydrogen; the most reactive of the metals
- 11. group 18 elements in the periodic table;the most stable and unreactive elements
- 14. a reaction that takes place when two or more substances react to form new substances
- 15. description of how a substance interacts with other substances, such as acids;chemical properties are observable only when a chemical change occurs
- 18. pure substance formed when non-metals combine
- 21. catalyst involved in chemical reactions in living things
- 22. atom that has become electrically charged because it has lost or gained electrons; a positive ion is an atom that has lost one or more electrons;a negative ion is an atom that has gained one or more electrons
- 24. 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
- 25. mass of one atom of an element calculated from the total number of protons,neutrons, and electrons of that atom; measured in atomic mass units (amu)
Down
- 1. anything that has mass and occupies space
- 2. combination of symbols that represent a compound; the formula identifies the elements in the compound and the amount of each element
- 4. number of protons in the nucleus of one atom of an element
- 5. group 2 elements in the periodic table; their reactivity is not as strong as that of the alkali metals
- 6. element that has both metallic and non-metallic properties
- 7. change of state from a solid to a liquid
- 9. group of atoms joined by covalent bonds
- 12. orbit of electrons around the nucleus of an atom
- 13. invisible negatively charged particle that orbits the nucleus of an atom
- 16. measure of atomic mass; 1 amu is equal to 1/12th the mass of a carbon 12 atom
- 17. pure substance formed when at least one metal and one non-metal combine
- 19. change that results when two or more substances react to create a different substance or substances; the new substances have completely different properties from the original ones
- 20. neutral particle in the nucleus of an atom
- 23. combination of pure substances; unlike a compound, the components of a mixture do not combine chemically and are not always in the same ratio