Properties of metter

2. Non-metals
Metals
Metaloids

3. Metals Non-metals
Metallic glow Dull, bright colours
Good conductors Weak conductors
Opaque Can be transparent
Change shape easily Brittle
Mostly solids Solids, liquids or gasses
High melting and boiling
points
Low to moderate
melting and boiling
points.

6.  Also called semi-metals
 Has some properties of metals and
some of non-metals
 Shiny or dull appearance
 Conducts electricity and heat, but not
as good as metals
 Electrical conductivity increases if
temperature increases

8.  Good conductors of electricity
 All metals and carbon
(graphite)
 Electrical conductivity
decreases if temperature
increase
 Test:
• Connect a piece of metal in
circuit as shown in picture
• Light bulb glows - Conductor

9. 1) Which metal has the highest
electrical conductivity?
Silver
2) Why then is copper used in
most electrical applieances?
Cheaper

10.  Weak conductors of electricity
 Non-metals
 example:
• Plastic and Rubber

11.  Conducts electricity, but not
as good as metals
 Metalois
 Electrical conductivity
increase if tempe-
rature increases
 Uses:
• LED’s
• Electronic appliances

12.  Thermal conductivity
• Flow of heat energy from
one point to another
 Thermal conductors
• Substances that conducts
heat well
• Metals
 Uses
• Heaters, kettle, stoves

13.  Thermal Insulators
• Substances that are poor
conductors of heat
• Non-metals
 Examples
• Glass, Plastic, Air
 Uses
• Insulation in homes,
thermal flasks, cooler
bags

14.  Substances that are strongly attracted
by magnets
 Iron, Nickel en Cobalt
 Magnetic alloys
• Ceramics: iron and metal oxides
• Alnico: Alluminium, nickel and cobalt
• Steel: Iron and carbon
 Uses:
• Compasses, cards, speakers

15. Soft Magnets Harde Magnets
 Is easily
magnetised
 Forms
temporary
magnets
 Difficult to
magnetise
 Forms
permanent
magnets