Presentation on theme: "Chapter 9 Compounds Lesson 1 Notes. Vocabulary Combining Elements Elements join together to create compounds. Compounds usually have different properties."— Presentation transcript:
Chapter 9 Compounds Lesson 1 Notes
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. H H O H O H Gas Liquid +
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: CO 2 = Carbon (C) and Oxygen (O) CaCO 3 = Calcium (Ca), Carbon (C), and Oxygen (O)
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).
How to Read a Chemical Formula Each capital letter in a formula represents an element on the periodic table. H 2 O NaCl The subset number tells you how many atoms of that element are in each molecule H 2 O HydrogenOxygen Sodium Chloride Two hydrogen
Let’s Practice What You Know! Let’s look that the chemical formula Fe 2 O 3 How 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 NaHCO 3 ? Think…Do I know the elements, number of each, number of total atoms…. H O H
Everyday Compounds Water is Earth’s most abundant element. The earth is made up of 75% water Your body is 66% water You use compounds everyday. Here are some everyday compounds: Everyday Compounds