Compounds--Pure substance composed of two or more different elements joined by chemical bonds
Compounds-Examples: Water H20 Hydrogen peroxide H202 Sodium chloride NaCl Carbon dioxide CO2
Mixtures -- A combination of two or more pure substances that are not chemically combined. Chem4kids.com
Mixtures—examples: Air Rocks Sand Koolaid Salad Pizza
BrainPOP movie www.brainpop.com Compounds and mixtures
. Compounds Have chemical formulas H2O Have physical and chemical properties different than the elements they are made from -H20 is a liquid but hydrogen and oxygen are gases Are chemical changes and can only be separated by chemical means, not physically Always have the same amounts of elements in it each time -water is H2O and it will always have 2 hydrogen atoms and 1 oxygen atom joined together
Mixtures Substances are held together by physical forces, NOT chemical Are physical changes Can be separated physically Each substance keeps its physical properties in the mixture Can have different amounts of a substance in it Chem4kids.com
Can you identify the following? You will be shown a series of photos. Tell if each photo represents an item composed of an element, compound, or mixture. Review: An element contains just one type of atom. A compound contains two or more different atoms joined together. A mixture contains two or more different substances that are only physically joined together, not chemically. A mixture can contain both elements and compounds.