Interpreting dot and cross diagrams

• What is a covalent bond?

  A covalent bond is a shared pair of electrons.
• What do covalent bonds form?

  Covalent bonding forms molecules.
• What are the properties of substances with small molecules?

  They have low melting and boiling points, and do not conduct electricity.
• What is the definition of a molecule?

  • A collection of two or more atoms held together by chemical bonds.
• What do dot and cross diagrams show?

  They show how electrons are shared in covalent bonds.
• What is the formula of water?

  The formula of water is H₂O.
• What is a double bond?

  A double bond consists of two shared pairs of electrons between two atoms.
• How do oxygen molecules bond together?

  Oxygen molecules consist of two oxygen atoms joined together by a double bond.
• How many covalent bonds can oxygen atoms form?

  Oxygen atoms can form two covalent bonds.
• What is the structure of a nitrogen molecule?

  The structure of a nitrogen molecule is N≡N, showing three shared pairs of electrons.
• How is a triple bond represented in nitrogen molecules?

  A triple bond is represented as N≡N.
• What are the properties of substances with small molecules?

  • Low melting points
  • Low boiling points
  • Do not conduct electricity
• What are the differences between single, double, and triple bonds?

  • Single bond: one shared pair of electrons
  • Double bond: two shared pairs of electrons
  • Triple bond: three shared pairs of electrons