chemical bonds

• What forms when atoms transfer or share electrons?

  Chemical bonds
• Why do atoms transfer or share electrons?

  To get full outer shells
• What are the three types of chemical bonds?

  • Ionic
  • Covalent
  • Metallic
• What does ionic bonding join together?

  Metal and non-metal elements
• What does covalent bonding join together?

  Non-metal elements
• What does metallic bonding join together?

  Metal elements
• What is an ion?

  A charged atom or molecule
• What happens to metal atoms during ion formation?

  They lose electrons from their outer shell
• What charge do metal atoms become when they lose electrons?

  Positively charged ions
• What do positive ions have more of than electrons?

  Protons
• What happens to non-metal atoms during ion formation?

  They gain electrons in their outer shell
• What charge do non-metal atoms become when they gain electrons?

  Negatively charged ions
• What do negative ions have more of than protons?

  Electrons
• Why do atoms become ions?

  To get a full outer shell of electrons
• How many electrons does the 1st shell need to be full?

  2 electrons
• How many electrons do other shells need to be full?

  8 electrons
• How do ionic bonds form?

  When electrons are transferred between atoms
• From where are electrons transferred in ionic bonding?

  From metal atoms to non-metal atoms
• What happens to metal and non-metal atoms during ionic bonding?

  Metal atoms lose electrons, non-metal atoms gain electrons
• What forms when a positive metal ion and a negative non-metal ion are created?

  An ionic compound
• What holds the positive metal ion and negative non-metal ion together?

  Strong electrostatic forces
• What are electrostatic forces?

  Attractive and repulsive forces between charged particles
• What structure do ionic compounds have?

  A regular structure called a lattice
• What is an ionic lattice?

  A giant structure of oppositely charged ions
• Why are ions held together in an ionic lattice?

  By strong electrostatic forces of attraction
• In which direction do electrostatic forces act in an ionic lattice?

  In all directions
• What are the characteristics of covalent bonds?

  • Form when electrons are shared between atoms
  • Join non-metal elements together
  • Require 2 electrons to make 1 bond
  • Electrons are shared in pairs
  • Atoms share electrons in their outer shells
• What is the structure of metals?

  Giant structures of atoms in a regular pattern
• What happens to the electrons in the outer shells of metal atoms?

  They are delocalised
• What do delocalised electrons do in metallic bonding?

  They move through the whole structure
• What forms when metal atoms share delocalised electrons?

  Metallic bonds
• What charge do metal atoms become due to delocalised electrons?

  Positive metal ions
• What holds positive metal ions and delocalised electrons together?

  Strong electrostatic forces of attraction
• Why are metallic bonds very strong?

  Due to strong electrostatic forces
• How are covalent bonds represented in dot and cross diagrams?

  • Overlap of atoms' outer shells
  • Pair of shared electrons drawn in the overlap
• How many outer electrons does nitrogen have?

  5 outer electrons
• How many more electrons does nitrogen need for a full outer shell?

  3 more electrons
• How does nitrogen achieve a full outer shell in ammonia?

  Nitrogen shares a pair of electrons with hydrogen
• How many overlaps are in the dot and cross diagram of ammonia?

  3 overlaps
• What is the significance of having a full outer shell for atoms?

  • Provides stability
  • Gives the electronic structure of a noble gas