Bonding 🫂

• What is an ion?


  An atom or group of atoms that have lost or gained electrons and have a charge.
• What are cations?

  Metal atoms that have lost electrons to form positively charged ions.
• What are anions?

  Non- metal atoms that have gained electrons to form negatively charged ions.
• What do cations and anions form?

  They are oppositely charged and form strong attractions which is an ionic bond.
• What do dot and cross diagrams show?

  How ionic compounds are formed.
• What is the difference between an atom and ion?

  Charge is the difference as atoms don't have an overall charge but ions do as they have either gained or lost electrons which gives them a charge.
• Explain the formation of ions in group 1,2,6 and 7.


  Group 1 & 2 - metals so lose electrons and form positive ions.

  Group 6 & 7 -non metals so gain electrons and form negative ions.
• What is the formulae of common polyatomic ions and the charges on them?

  -Nitrate (NO3)

  -Nitrite (NO2)

  -Sulfate (SO4)

  -Sulfite (SO3)2

  -Hydroxide (OH)

  -Ammonium (NH4)+

  -Carbonate (CO3)2

  -Phosphate (PO4)3

  -Acetate (C2H3O2)-
• what is the difference between the use of -ide and -ate endings in the name of compounds?

  -ide ending = compound contains two elements.

  -ate ending = compound contains three or more elements one which is (O2).
• What are the advantages of models that show structures?


  2D representations- simple and great at showing atoms and their connections.

  Dot and cross diagrams- show how compounds or molecules are formed and where electron and ion bonds come from.

  3D models- show the arrangement of ions.

  Ball and stick models- more realistic, help visualise structures of lattice.
• What are the disadvantages of models that show structures?


  2D representations- don't show shape of substance or size of atoms.

  Dot and cross diagram- don't show size of atoms/ions or how they're arranged.

  3D models- only show outer layer.

  Ball and stick models- don't show correct scales of atoms or ions and have big gaps in between.