Term 2 Topic 4 Some properties of metals, semi-metals and non-metals

• Ask the learners which elements are the most on the Periodic Table. [Metals]
• They must also identify which elements are the least. [Semi-metals]
• Establish if they know why aeroplanes are not made of iron.

[Possible answers: Iron is too heavy; the aeroplane will not be able to take off; the aeroplane would never be able to fly; etc.]

• Explain to the learners what ‘properties’ in chemistry means.

[Chemical Property Definition: A chemical property is a property or behaviour of a substance when it undergoes a chemical change or reaction which can include toxicity, oxidation, and flammability. Iron will rust once it becomes oxidized].

• Tell the learners that physical properties include colour, odour, melting point, boiling point, density, texture, appearance, etc.
• Present an overview of the properties of the different elements by using Presentation 2: Properties of metals, semi-metals and non-metals.

• The learners give feedback.
• They can also share interesting facts that captured their attention.
• Complete Worksheet C: Properties of metals and non-metals.
• Teacher to use Worksheet C: Memorandum to mark the learners’ work.

• Inform the learners that they will be working in groups and compete against one another.
• Instructions:
  • Select 3 metal elements and 3 non-metal elements.
  • Write one property of each selected element.

• The groups brainstorm ideas and jot down the elements which they had selected.
• They can use any resource materials, e.g. notebooks, textbook, etc.
• Each group gets an opportunity to ask another group a question and points are allocated.

• Mention a few elements that we usually use daily and give the learners an opportunity to share and expand their knowledge on the elements. A few examples:
  • Chlorine [clean swimming pools].
  • Iron [use to manufacture steel and stainless steel].
  • Oxygen [Humans and animals breathe in oxygen; our bodies need it for energy].
  • Copper [used in electrical wires; it is good conductors of electricity].
  • Aluminium [cooking pots and pans; constructing doors and windows].
  • Gold and Silver [jewellery].
• Show both video clips:

Video Clip 2: Slide Show - The Periodic Table.

Video Clip 3: Slide Show - The Periodic Table.