Bonding, structure, and the properties of matter

• What are the three types of strong chemical bonds?

  Ionic, covalent, and metallic
• How do ionic bonds form?

  They form between oppositely charged ions.
• What characterizes covalent bonding?

  Atoms share pairs of electrons.
• What is the nature of metallic bonding?

  Atoms share delocalised electrons.
• In which types of compounds does ionic bonding occur?

  In compounds formed from metals combined with non-metals.
• What types of materials exhibit metallic bonding?

  Metallic elements and alloys.
• How can students explain chemical bonding?

  In terms of electrostatic forces and the transfer or sharing of electrons.
• What happens when a metal atom reacts with a non-metal atom?

  Electrons in the outer shell of the metal atom are transferred.
• What charge do metal atoms acquire when they lose electrons?

  They become positively charged ions.
• What charge do non-metal atoms acquire when they gain electrons?

  They become negatively charged ions.
• What electronic structure do ions produced by metals in Groups 1 and 2 and non-metals in Groups 6 and 7 have?

  The electronic structure of a noble gas (Group 0).
• How can the electron transfer during the formation of an ionic compound be represented?

  By a dot and cross diagram.
• What should students be able to draw for ionic compounds formed by metals in Groups 1 and 2 with non-metals in Groups 6 and 7?

  Dot and cross diagrams.
• How does the charge on the ions produced relate to the group number of the element?

  The charge corresponds to the group number in the periodic table.
• From which groups should students work out the charge on the ions of metals and non-metals?

  Metals in Groups 1 and 2, and non-metals in Groups 6 and 7.
• What is an ionic compound?

  A giant structure of ions.
• What holds ionic compounds together?

  Strong electrostatic forces of attraction between oppositely charged ions.
• How do the forces in an ionic lattice act?

  They act in all directions.
• What can students deduce from a diagram of a compound's structure?

  Whether a compound is ionic.
• What are the limitations of using dot and cross, ball and stick, and two and three-dimensional diagrams?

  They may not accurately represent a giant ionic structure.
• How can students work out the empirical formula of an ionic compound?

  From a given model or diagram showing the ions in the structure.
• What should students be familiar with regarding sodium chloride?

  The structure of sodium chloride.
• What happens when atoms share pairs of electrons?

  They form covalent bonds.
• What type of substances may consist of small molecules?

  Covalently bonded substances.
• What are some examples of substances with giant covalent structures?

  Diamond and silicon dioxide.
• How can covalent bonds in molecules and giant structures be represented?

  In various forms, including dot and cross diagrams.
• How can students represent polymers?

  In the form where n is a large number.
• What are the properties of metals in terms of their structure?

  They consist of giant structures of atoms arranged in a regular pattern.
• What happens to the electrons in the outer shell of metal atoms?

  They are delocalised and free to move through the whole structure.
• What gives rise to strong metallic bonds?

  The sharing of delocalised electrons.
• What are the three states of matter?

  Solid, liquid, and gas.
• What occurs at the melting point?

  Melting and freezing take place.
• What occurs at the boiling point?

  Boiling and condensing take place.
• How can particle theory explain changes of state?

  It helps to explain melting, boiling, freezing, and condensing.
• What does the amount of energy needed to change state depend on?

  The strength of the forces between the particles of the substance.
• How does the nature of the particles involved relate to bonding and structure?

  It depends on the type of bonding and the structure of the substance.
• What is the relationship between the strength of forces and melting/boiling points?

  The stronger the forces, the higher the melting and boiling points.
• What are the limitations of the simple model of states of matter?

  It does not account for forces and represents all particles as solid spheres.
• What should students be able to predict regarding states of substances?

  The states of substances at different temperatures given appropriate data.
• How can students explain the different temperatures at which changes of state occur?

  In terms of energy transfers and types of bonding.