Chemistry 2: Bonding KNOWLEDGE ORGANISER (triple) KPI:C12 (p33) Polymers Polymers are very large molecules made when many smaller molecules join together, end to end. The smaller molecules are called monomers. In general: lots of monomer molecules → a polymer molecule The polymers formed are long chains of repeating units. For example poly(ethane) has a molecular formula of the polymer is (C2H4)n KPI:C9 (p28 - 30) Describe ionic bonds and ionic compounds Ionic Compounds Are Balanced. Table salt is an example of an ionic compound. Sodium and chlorine ions come together to form sodium chloride, or NaCl. The sodium atom in this compound loses an electron to become Na+, while the chlorine atom gains an electron to become Cl-. KPI:C13 (p35) Describe the structures and bonding in metals Metallic bonding is the force of attraction between delocalised electrons and the metal atoms. There are strong forces of electrostatic attraction between the positive metal ions and the shared negative electrons Most metals are solid at room temperature They are good conductors of electricity and heat They are malleable Alloys are harder than pure metals KPI:C10 (p31 - 32) Formation of covalent compounds A covalent compound is made when two or more nonmetal atoms bond by sharing electrons. The shared electrons between two nonmetal atoms is called a covalent bond. Covalent bonds are formed when two atoms begin sharing electrons. The electrons are attracted to the positively charged nuclei of the atoms. KPI: C14 (p36 - 37) Describe the properties of the three states of matter KPI:C11 (p33 - 34) Describe the structure and property of giant covalent compounds Giant covalent structures contain a lot of non-metal atoms, each joined to adjacent atoms by covalent bonds. The atoms are usually arranged into giant regular lattices - extremely strong structures because of the many bonds involved.