Bonding and Types of Substance

Cards (96)

  • Ions
    Charged particles formed when atoms lose or gain electrons
  • Ionic bonds
    • Forces of attraction that hold atoms together when bonds form
    • Energy is released from the atoms, making them more stable
    • Less reactive
  • Noble gases
    Atoms with a full outer electron shell, the most stable atoms
  • Formation of sodium chloride
    1. Sodium atom loses electron
    2. Chlorine atom gains electron
    3. Ions form
    4. Ionic bond forms
  • Dot and cross diagrams can be used to show what happens when ions are formed
  • Cations
    Positive ions formed when metal atoms lose electrons
  • Anions
    Negative ions formed when non-metal atoms gain electrons
  • Electrostatic forces

    Forces of attraction between oppositely charged objects that hold ions together in an ionic bond
  • Atoms that easily form ions will have either a nearly full or a nearly empty outer electron shell
  • Ion formation in groups 1, 2, 6 and 7
    • Group 1: 1 electron lost, 1+ charge
    • Group 2: 2 electrons lost, 2+ charge
    • Group 6: 2 electrons gained, 2- charge
    • Group 7: 1 electron gained, 1- charge
  • Formation of magnesium oxide ionic bond
    1. Magnesium atom loses 2 electrons
    2. Oxygen atom gains 2 electrons
    3. Ionic bond forms
  • Aluminium atom loses 3 electrons when its ion is formed
  • Bromine is in group 7 of the periodic table
  • Bromide ion has the same number of electrons as a bromine atom
  • Bromide ion

    Bromine atom that has gained 1 electron
  • Hydrogen ion (H+) is just a proton
  • Potassium (K) in group 1 forms a 1+ ion
  • Selenium (Se) in group 6 forms a 2- ion
  • Sulfur atom contains 16 protons
  • Sulfur atom forms S2- ions
  • Ionic lattice
    Regular repeating arrangement of oppositely charged ions held together by strong electrostatic forces
  • Ionic compounds form crystals due to their regular lattice structure
  • There are seven basic crystal structures
  • Ionic compounds are electrically neutral, with the same number of positive and negative charges
  • Working out ionic formulae

    Use ion charges to determine the number of each ion needed for electrical neutrality
  • Polyatomic ions are groups of two or more atoms that have become charged
  • Compound names ending in -ate contain oxygen
  • Compound names ending in -ide do not contain oxygen
  • Ionic compounds contain ions, not atoms or molecules
  • Strong electrostatic forces of attraction between oppositely charged ions

    Require high energy to overcome, resulting in high melting and boiling points
  • Highly charged ions (e.g. Mg2+) attract other ions more strongly, increasing melting point
  • Ionic compounds conduct electricity when molten or in aqueous solution, but not in solid state
  • Anode
    Positive electrode that attracts negative ions (anions)
  • Cathode
    Negative electrode that attracts positive ions (cations)
  • It is the movement of ions that enables ionic compounds to conduct electricity, not electrons
  • Magnesium oxide is insoluble in water
  • Covalent bonds
    Strong bonds formed by the sharing of pairs of electrons between atoms
  • Molecular substances contain groups of atoms that are held together by strong bonds called covalent bonds
  • Molecular formula
    Shows the number of atoms of each element in a molecule
  • Molecular formulae
    • CHNO
    • CHMO
    • HO
    • CHO