Covalent bonds

Let’s Share! What is a covalent bond? Unit 3 Lesson 4 Ionic, Covalent, and Metallic Bonding Let’s Share! What is a covalent bond? A covalent bond forms when atoms share one or more pairs of electrons. When two nonmetal atoms bond, a large amount of energy is needed for either atom to lose an electron. So they bond by sharing electrons. In a covalent bond, the shared electrons fill empty spaces in the outermost electron shell of each atom. Copyright © Houghton Mifflin Harcourt Publishing Company

Unit 3 Lesson 4 Ionic, Covalent, and Metallic Bonding What is a molecule? When atoms join together with covalent bonds, they form a type of particle called a molecule. A molecule is a group of atoms held together by chemical bonds. A molecule is the smallest unit of a compound that can be identified as that compound. Copyright © Houghton Mifflin Harcourt Publishing Company

Unit 3 Lesson 4 Ionic, Covalent, and Metallic Bonding What is a molecule? In a water molecule, two hydrogen atoms form covalent bonds with a central oxygen atom. Copyright © Houghton Mifflin Harcourt Publishing Company

Covalent Bond Introduction Video https://www.youtube.com/watch?v=LkAykOv1foc Write three sentences describing what you saw in the video (to prove you have been paying attention)

What properties do most covalent compounds share? (Low solubility) Unit 3 Lesson 4 Ionic, Covalent, and Metallic Bonding What properties do most covalent compounds share? (Low solubility) Some covalent compounds dissolve in water. Other covalent compounds do not. Wax molecules have a stronger attraction to other wax molecules than they have to water molecules. This is why wax does not dissolve in water. Copyright © Houghton Mifflin Harcourt Publishing Company

Unit 3 Lesson 4 Ionic, Covalent, and Metallic Bonding What properties do most covalent compounds share? (Low melting and boiling points) When a covalent compound melts or boils, the covalent bonds holding the molecules together do not break as ionic bonds in an ionic compound do. Instead, one molecule separates from another. Because molecules separate easily from other molecules, they tend to have lower melting and boiling points than ionic compounds. Copyright © Houghton Mifflin Harcourt Publishing Company

Unit 3 Lesson 4 Ionic, Covalent, and Metallic Bonding What properties do most covalent compounds share? (Poor electrical conductivity) Most covalent compounds are poor conductors of electric current in both solid and liquid form. Unlike ions, which are charged, molecules are neutral. So, even in a liquid in which molecules can move around, the compound cannot conduct electric current. Copyright © Houghton Mifflin Harcourt Publishing Company