Elements and Compounds

1. Elements and Compounds Test Review By PresenterMedia.com

2. Compounds are all around us. Water H2O Identify the elements that make up these common compounds. Hydrogen and Oxygen Sodium and Chlorine Salt NaCl

3. What are the 2 most common elements in the atmosphere? Nitrogen (N) 78% Oxygen (O) 21%

4. What are the 2 most common elements in the ocean? Oxygen (O) Hydrogen (H)

5. Elements and Compounds are very different. Elements Compounds • Pure substances made of only one type of atom. • Cannot be broken down into a smaller piece and have the same properties. • Represented by one chemical symbol that can have only 1 capital letter. • 2 or more elements chemically bonded together. • Can be broken down into elements. • Represented by a chemical formula that must have 2 or more capital letters.

6. Element Represented by only one figure because it is only one type of atom. Compound Represented by two or more different figures bonded together because compounds are made of 2 or more elements. Mixture Represented by figures of both elements and compounds. Visual Representations How can we tell the difference between elements, compounds and mixtures.

7. Use the periodic table to determine the elements in the compound. NaCl I Cl Na Na Which of the above elements is not in the compound?

8. Look at each of the following and decide if it can be investigated. Investigable vs. Non-investigable Remember that something is investigable if it can be tested in the classroom with the materials available in the time available and will not place anyone or anything in dangerous conditions. If the above conditions cannot be met then the question is Non-investigable. Why do leaves change colors? Why do leaves change colors? Non-investigable Why did the plant’s roots grow in water? Non-investigable How do plants absorb water? Non-investigable How much did the plant grow in one week? Investigable

9. Na O H NaCl Be Cl Elements vs. Compounds Which of the samples above is not an element?