3.3 Chemical properties of metals and non-metals

Summary: Figure 1 shows the Danakil Desert. Hot, acidic water bubbles from the ground and fumes of acidic gases fill the air. Tags: science oxford-science student-book-7 chemistry Created: 2026-05-19 Last Updated: 2026-05-19

After this topic, you will be able to:

• define chemical properties
• describe the chemical properties of metals and non-metals.

Think back

1. Define a compound.
2. Name the two Elements whose Atoms are in sulfur dioxide.
3. Copy and complete the sentence: The pH of an acidic solution is less than blank.

Key idea Metal and non-metal elements have different chemical properties. Most metals react with oxygen to make basic oxides. Most non-metals react with oxygen to make acidic oxides.

Key words acid rain, chemical property

Table 1 Decide whether each element in Table 1 is a metal or non-metal, or whether it might be a metalloid. Give reasons for your decisions. Table 1 Melting point in °C Oxide element A 1085 basic element B −102 acidic element C 938 can act as both an acid and a base

Figure 1 shows the Danakil Desert. Hot, acidic water bubbles from the ground and fumes of acidic gases fill the air.

Figure 1The Danakil Desert.

One of the acidic gases in the Danakil Desert is sulfur dioxide. Carbon dioxide, hydrogen chloride, and hydrogen sulfide are also part of the acidic mixture.

How do non-metals react with oxygen?

Many non-metal elements react with oxygen. The Products are oxides. For example:

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Most non-metal oxides are gases at 20 °C. They dissolve (mix) in water to form acidic solutions, with a pH of less than 7.

Sulfur dioxide and nitrogen dioxide are acidic gases. They are formed when fossil Fuels burn in car engines. The products of these burning reactions dissolve in rain. This makes the rain acidic.

Acid rain damages trees, like in Figure 2. Acid rain also makes lakes acidic.

Figure 2Acid rain damages trees.

A Predict whether the pH of nitrogen dioxide is less than 7 or more than 7. Explain your answer.

How do metals react with oxygen?

Many metals react with oxygen. The products are oxides. For example:

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Most metal oxides are solid at 20 °C. Many metal oxides are basic. This means that they form alkaline solutions if they dissolve in water, with pH more than 7. Figure 3 shows a metal oxide.

Figure 3Magnesium oxide is basic. It is solid at room temperature.

B An oxide of element X dissolves in water to make a solution of pH 5. Predict whether element X is a metal or non-metal.

What are chemical properties?

There is a pattern in the Chemical Reactions of elements with oxygen:

• most non-metals react with oxygen to make acidic oxides
• most metals react with oxygen to make basic oxides.

The chemical reactions of elements with oxygen are examples of chemical properties. The chemical properties of a substance describe its chemical reactions.

C Describe one chemical property of a typical metal. Describe one physical property of a typical metal.

Summary questions

1. Sort these properties into two lists: properties of metal oxides and properties of non-metal oxides. Properties: acidic, basic, gas at 20 °C, solid at 20 °C.
2. Write the meaning of chemical properties.
3. A teacher reacts sodium with oxygen, and then sulfur with oxygen. Compare the products of the two reactions.