Chemistry - Chemical Bonds, Ionic, Covalent and Metallic

• There are three types of strong chemical bonds, ionic, covalent or metallic, each have different properties.
• Ionic bonds are bonds between a metal and a non-metal.
• Atoms always try and gain a full outer shell. When a metal and non-metal react, the metal atom loses electrons and forms a positively charged ion and the non-metal will gain electrons to fill its outer shell, and form a negatively charged ion.
• The attraction between oppositely charged ions is called an electrostatic force
• In ionic bonding, the two ions are strongly attracted by electrostatic forces, which becomes an ionic bond.
• Metals are good conductors because they contain delocalised electrons that move freely through the lattice structure.
• An ionic compound is a compound that contains ionic bonds.
• Ionic compounds have regular structures, called a giant ionic lattice which is held together by the strong electrostatic forces of attraction between positively charged ions.
• All ionic compounds have similar properties:

  • They have high melting and boiling points because of the many strong bonds between the atoms that would take a lot of energy to break.
• All ionic compounds have similar properties:

  • They have high melting and boiling points because of the many strong bonds between the atoms that would take a lot of energy to break.
  • When they are solid, the ions are held strongly in place and can't conduct electricity.
  • However, when they melt, the electrons are free to move and they can carry a charge.
  • Or, if the ionic compound dissolves in water, it may carry a charge as the ions are free.
• A covalent bond is strong electrostatic forces of attraction between a shared pair of electrons and positive nuclei.
• Metals are arranged in giant metallic lattices. They are defined as: electrostatic forces of attraction between positive cations and a sea of delocalised electrons.
• Delocalised electrons are free to move anywhere.
• Malleable and Ductile:

  • Malleable means they can be hammered into a shape.
  • Ductile means they can be drawn into wires.

  Metal cations are arranged in layers which can easily slide over one another.
• Properties of transition metals:

  • High melting/boiling points because there are strong electrostatic forces of attraction between cations and a sea of delocalised electrons which require a lot of energy to break.
  • High densitity because they are arranged in a giant lattice.
  • They form ionic coloured compounds.
  • Can be used as a catalyst.
  • Can conduct electricity because there are delocalised electrons which are free to move and carry charge.
• Transition metals can conduct electricity because they contain delocalised electrons which are free to move and carry charge.
• Describe the structure of a metal:

  Metals have strong electrostatic forces of attraction between positive cations and a sea of delocalised electrons. They are arranged in giant lattices.
• Explain why metals are malleable + conduct electricity:

  Malleable means that the material can be hammered into shape. Metals are malleable because they are arranged in layers, meaning they can easily slide over each other when pressure is applied. The delocalised electrons fill the spaces between the layers of positive cations, meaning that no matter the shape the metal is hammered into, the delocalised electrons will hold the metal together.

  Metals can conduct electricity because there are delocalised electrons which are free to move through the structure of the metal and transfer charge.
• Ionic compounds:

  • Have a regular lattice structure.
  • There are strong electrostatic forces of attraction between oppositely shared ions.
  • They have high melting points and high boiling points.
• What is the proton number of lithium?

  3
• An ionic compound can move electricity when it is molten.
• An isotope is an atom of the same element with a different number of neutrons but the same protons.
• The mass number tells us the amount of protons and neutrons.