Materials: Metals and Non-Metals

• Distinguish physical properties of metals (lustrous, malleable, ductile, good conductors, sonorous) from non-metals (dull, brittle, poor conductors, non-sonorous, with exceptions).
• Understand basic chemical properties: reaction of metals with oxygen, water, and acids.
• Recognise common exceptions to typical metal/non-metal properties.

1. Metals are typically shiny (lustrous), can be hammered into sheets (malleable), drawn into wires (ductile), good conductors of heat/electricity, and produce a ringing sound (sonorous).
2. Non-metals are typically dull, brittle (break when hammered), poor conductors, and non-sonorous.
3. Exceptions: Iodine is a non-metal but lustrous; graphite (a non-metal, form of carbon) conducts electricity; mercury is a metal but liquid at room temperature.
4. Most metals react with oxygen to form metal oxides, which are usually basic; most non-metal oxides are acidic.
5. Metals generally react with dilute acids to release hydrogen gas.

A student hammers a shiny grey solid and it breaks into pieces instead of flattening. Is it likely a metal or non-metal?

Breaking (not flattening) when hammered indicates brittleness,
a typical non-metal property, despite the shiny appearance
(which resembles the exception of iodine).

• Assuming shininess alone proves something is a metal (iodine is a shiny non-metal).
• Assuming all non-metals are poor conductors (graphite conducts electricity well).
• Forgetting mercury is an exception — a metal that is liquid at room temperature.

• Name one non-metal that conducts electricity.
• Name one metal that is liquid at room temperature.

Open the Practice tab for graded questions on Materials: Metals and Non-Metals.