1. 1
   A student examines a piece of pure copper wire and a sample of pure sulfur powder, both of which are labelled by the teacher as elements.

   (a)

   A student is told that a piece of pure copper wire is an element. Which statement correctly defines an element?

   [1 mark]

   • AA substance made of only one sort of atom
   • BA substance made of two or more different atoms chemically joined
   • CAny substance that conducts electricity
   • DA substance that can be separated by physical methods

   (b)

   Which chemical symbol correctly represents an atom of sulfur?

   [1 mark]

   • ASu
   • BS
   • CSl
   • DSo

   (c)

   Explain why the copper wire is classified as an element rather than a compound or a mixture.

   [2 marks]

   Total for question 1: 4 marks

2. 2
   A teacher shows the class a jar of iron filings, a jar of gold dust, and a sample of graphite, explaining that all three are examples of elements.

   (a)

   Approximately how many different elements are currently known and shown in the periodic table?

   [1 mark]

   • AAbout 1000
   • BAbout 10
   • CAbout 100
   • DAbout 20

   (b)

   Which of the following is the correct chemical symbol for iron?

   [1 mark]

   • AIn
   • BI
   • CIr
   • DFe

   (c)

   Explain why iron and gold are considered different elements, even though both are metals.

   [2 marks]

   Total for question 2: 4 marks

3. 3
   A group of students is given three unlabelled samples: pure sodium metal, pure chlorine gas, and a mixture of sodium chloride crystals and sand grains.

   (a)

   Identify which of the three samples are elements, and explain your reasoning for each.

   [3 marks]

   (b)

   Using the three samples described, explain the difference between an element and a mixture.

   [4 marks]

   Total for question 3: 7 marks

4. 4
   A chemistry textbook explains that there are about 100 known elements, each given its own unique chemical symbol, and that all of these elements are organised together in the periodic table.

   (a)

   Describe how chemical symbols are used to represent elements, and describe how the periodic table organises all of the known elements.

   [6 marks]

   (b)

   Evaluate why using chemical symbols and the periodic table is more useful to chemists than simply writing the full names of elements in different languages.

   [6 marks]

   Total for question 4: 12 marks

End of questions