1. 1.A pure substance made of one type of atom 2.Oxygen, Silicon, Aluminum 3.Oxygen and Carbon 4.Oxygen and Hydrogen 5.Oxygen and Nitrogen 6.Element are one type of atom and compounds are more than one type of atom. 7.To organize the elements by properties 8.One to two letter symbol that represents an element, Ne, H, Li, Pb

2. 9.Compound, 2 or more types of atoms 10. Chemical change is a change that creates a new substance 11. Physical changes do not create a new substance. 12. new substance 13.Color change, temperature change, precipitate formation, gas formation

3. 14.Vinegar and baking soda CaCl2 + baking soda Citric acid+borax+indicator CaCl2+water 15.metals, nonmetals, and metalloids compare by their properties 16. shiny, conductors, malleable 17. dull, brittle, insulators 18.Semiconductors, metallic luster, brittle 19.Metals left, nonmetals right, and metalloids stair step