2. Chapter 2: Chemical Bonds and Compounds Elements Combine to Form Compounds Chemical Bonds Hold Compounds Together Ionic/Covalent Bonds Terms 100 200 300 400 500

3. Most substances around us are known as _____________. Compounds

4. The atoms of different elements are held together in compounds by __________ _________. Chemical Bonds

5. How do the properties of a compound compare with the properties of the elements that make it? They are often quite different. For example, water is made of 2 hydrogen atoms and 1 oxygen atom. At room temperature, H and O are both colorless, odorless gases, and they remain gases down to extremely low temperatures. Water, however, is a liquid at temps up to 100 degrees Celsius and a solid below O degrees Celsius.

6. Why is the ratio of atoms in a chemical formula so important? Different ratios of elements indicate different compounds.

7. Which ratio correctly depicts NO 2 ? A.2:1 B.1:1 C.1:2 D.None of the above C. 1:2

8. What type of charge does an atom’s nucleus contain? Explain why. Positive charge b/c only protons (+) and neutrons (no charge) are contained in the nucleus

9. What are formed when atoms gain or lose electrons? Ions

10. Using your periodic table What type of compound is Potassium Bromide (KBr)? Ionic Compound—why??

11. True or False. In a covalent bond, the atoms usually form regular-shaped (lattice) structures. False; ionic bonds.

12. What are two of the three forms of the element carbon that your textbook refers to? 1.Diamond- hardest natural substance, useful for cutting other substances, and made entirely of carbon. 2.Graphite- dark, slippery component of pencil “lead,” and form two-dimensional layers. 3.Fullerene- contains large molecules, one type is shaped like a soccer ball.

13. In a covalent bond, two ________ are bonding to form a covalent compound. Nonmetals

14. What are being stolen in an ionic bond? Electrons

15. Which of the following is NOT a property a metal? A.They are good conductors of electricity B.They are good conductors of heat C.They are NOT easy to bend D.They are shiny C. They are NOT easy to bend

16. In this particular bond, electrons are shared equally. Covalent

17. What is at least ONE property of a metal? 1.Conduct electricity well 2.Conduct heat well 3.Easily pounded/shaped/bent

18. It is describing the number of atoms that particular element contains in that compound. What does a subscript tell us when written in a chemical formula?

19. What is a metallic bond? A bond in which electrons are shared equally among the atoms of a metal.

20. A molecule is a group of atoms held together by ______ bonds. Covalent

21. Please list at least 3 types of bonds. Chemical bonds are what hold atoms together in compounds. Chemical bonds can effect the compound’s properties. 1.Ionic bonds 2.Covalent Bonds 3.Polar Covalent Bonds 4.Metallic Bonds

22. Using your periodic table, please determine if C 2 H 6 O (ethanol) if it is a covalent or ionic compound. Covalent Compound