2 Vocabulary Chemical Formula – a shorthand way to describe a compound. Chemical Reaction – process in which one or more substances are changed into one or more DIFFERENT substances.
3 + Combining Elements Elements join together to create compounds. Compounds usually have different properties from the elements that make them up. For example:Water is created by chemically joining two gasses.HOGasLiquid+I tr
4 Many Compounds Are found in nature Others are created in a laboratory Some compounds are made up of just two compounds and others are made up of several.For example:CO2 = Carbon (C) and Oxygen (O)CaCO3 = Calcium (Ca), Carbon (C), and Oxygen (O)
5 Making and Breaking Compounds To form or break a compound, a chemical REACTION must occur.This will only happen if energy is added (most commonly in the form of heat).
6 How to Read a Chemical Formula Each capital letter in a formula represents an element on the periodic table.H2O NaClThe subset number tells you how many atoms of that element are in each molecule H2OHydrogenOxygenSodiumChlorideTwo hydrogen
7 Let’s Practice What You Know! Let’s look that the chemical formula Fe2O3How many atoms of Iron are there? Oxygen?Write the chemical formula for the molecule you see here:What do you know about the chemical formula for sodium bicarbonate NaHCO3?Think…Do I know the elements, number of each, number of total atoms….HO
8 Everyday Compounds Everyday Compounds Water is Earth’s most abundant element.The earth is made up of 75% waterYour body is 66% waterYou use compounds everyday. Here are some everyday compounds:EverydayCompounds