2.1 Elements
Summary: Look at Figures 1, 2, and 3. What do the objects have in common? 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 an element and list some examples of Elements
- describe what the Periodic Table shows and use it to find a named element.
Think back
- What is a substance?
- Name three substances.
- What are properties?
Key idea An element is a substance that cannot be broken down into other substances. Every element has its own chemical symbol. The Periodic Table lists and organizes all the elements.
Key words element, Periodic Table, chemical symbol
Look at Figures 1**,** 2**, and** 3**. What do the objects have in common?**
All of these objects contain platinum. Catalytic converters change harmful car exhaust fumes into less harmful ones. Pacemakers are used to help the heart beat regularly.
Platinum is a shiny substance that is not damaged by air or water. It is easy to make platinum into different shapes. These properties make platinum suitable for the uses in Figures 1, 2, and 3.
Figure 1Jewellery.
Figure 2A catalytic converter.
Figure 3A heart pacemaker.
Platinum is an example of an element. An element is a substance that cannot be broken down into other substances. You may have heard of some elements, including gold, silver, oxygen, chlorine, and helium.
A Predict whether or not platinum can be broken down into other substances. Explain your decision.
How many elements?
There are millions of materials. Every material, and everything in the Universe, is made up of one or more elements. There are about 100 elements.
The Periodic Table (Figure 4) lists all the elements. In the Periodic Table, elements with similar properties are put into groups.
Figure 4The Periodic Table lists all the elements. Full text alternative to the content
Literacy skills Listen to your teacher read the names of the elements in the row of the Periodic Table that starts with sodium. In pairs, take it in turns to practise pronouncing the words correctly.
B Give the approximate number of elements, to the nearest hundred.
What are chemical symbols?
Every element has its own chemical symbol. This is a one- or two-letter code for the element. Scientists all over the world use the same Chemical Symbols, no matter what language they speak or write in.
Table 1 shows some chemical symbols. The first letter of a chemical symbol is a capital letter. The second letter is lowercase. Table 1 Elements and their chemical symbols. Name of element
Chemical symbol
carbon
C
nitrogen
N
chlorine
Cl
gold
Au
iron
Fe
tungsten
W
For some elements, their chemical symbol is the first letter of its English name. For other elements, the chemical symbol is the first and second or first and third letters of its name.
The chemical symbols of some elements come from their Latin names, for example, aurum for gold and ferrum for iron. The chemical symbol of tungsten comes from its German name, Wolfram.
C Write down the chemical symbols of the elements carbon, chlorine, gold, and iron.
Summary questions
- Copy and complete the sentences. A substance that cannot be broken down into other substances is called an element/a mixture. There are about 100/200 elements. The elements are listed in the particle model/Periodic Table. Every element has its own one- or two-letter code, called its chemical letter/symbol.
- Find these elements in the Periodic Table: carbon, calcium, cobalt, copper, xenon, praseodymium. Write down the chemical symbol of each element in the list.
- Identify the three elements in this list of substances: argon, air, carbon dioxide, methane, nitrogen, water, krypton. Explain your answers.