Bonds, Structure and Properties of Matter

• What are the three types of bonds

  • Ionic bonding
  • Cavalent bonding
  • Metallic bonding
• What is an ion

  • An ion is an electrically charged atom or group of atoms formed by the loss or gain of electrons
  • This loss or gain of electrons takes place to obtain a full outer shell of electrons
  • Negative ions are called anions and form when atoms gain electrons, meaning they have more electrons than protons
  • Positive ions are called cations and form when atoms lose electrons, meaning they have more protons than electrons
  • All metals lose electrons to other atoms to become positively charged ions
  • All non-metals gain electrons from other atoms to become negatively charged ions
• Dot and cross diagrams

  • These show the arrangement of the electrons in an ionic compound
  • The electrons are shown as dots and crosses
  • The charge of the ion is spread evenly which is shown by using brackets
  • The charge on each ion is written at the top right-hand corner
• Ionic bonds:

  • Takes place when metals and non-metals react by transferring electrons
  • The atoms involved are oppositely charged particles (known as ions) in which electron transfer occurs
  • The opposite charges attract through electrostatic forces
• Covalent bonds:

  • non-metal atoms share pairs of electrons between each other
• • Metallic bonds:
  • This type of bonding occurs in metals and metal alloys (mixtures of metals)