Lesson 7 — Activity 3: Metals, Non-metals, and Metalloids



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You now know that everything is made of atoms and molecules. You also know everything is also either a pure substance or a mixture. You are now ready to learn about one of the properties of elements. In this activity, you learn about metals and non-metals.

Remember, elements are the building blocks of matter. An element is a substance that is made from only one type of atom. It cannot be further broken down using any chemical means.

All elements are either metals, non-metals, or metalloids, and you will find them on the periodic table.

The periodic table is organized like a big grid. Each element is placed in a specific location because of its atomic structure. As with any grid, the periodic table has rows (left to right) and columns (up and down). Each row and column has specific characteristics. You will learn more about the periodic table in an upcoming lesson.

 

Look at the periodic table below.


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Look at the dark green elements on the right of the table. These seven elements are called metalloids. They form what looks a bit like a staircase in the table. They are located to the right of the metals and to the left of the non-metals. Metalloids have some properties in common with metals and some in common with non-metals.


 

Metalloids share many similar properties:

  • They appear to be metal in appearance but are brittle.
  • They can generally form alloys with metals.
  • Some metalloids such as silicon and germanium become electrical conductors under special conditions. These are called semiconductors.
  • They are solids under standard conditions.
  • They are mostly non-metallic in their chemical behaviour.

 

Metals are shiny, malleable, and ductile. Malleable means that they can be pounded into flat sheets. Ductile means that they can be stretched into long wires. Metals also conduct electricity.



Malleable - able to be flattened into a thin sheet or foil

 

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Ductile - able to be pulled into a long thin wire

 

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Everything to the left of the staircase is a metal, and they make up most of the periodic table. Look at some of the elements that are metals: magnesium (Mg), iron (Fe), gold (Au), and nickel (Ni).

Non-metals are the elements to the right of the staircase. They are in yellow. They can be a solid or a gas. Solid non-metals are dull, brittle elements. Most do not conduct electricity. The only exception is carbon, which does conduct electricity. Because most do not conduct electricity, non-metals are called insulators. Some of the elements that are non-metals are oxygen (O), sulphur (S), chlorine (Cl), and fluorine (F).




Click on the Play button to watch a video that further explains metals, non-metals, and metalloids.