EASY
Lower Secondary Stage 8
IMPORTANT
Earn 100

The compound lithium oxide has the formula Li2O. Which statement is correct?

33.33% studentsanswered this correctly

Important Questions on Elements, Compounds and Mixtures

EASY
Lower Secondary Stage 8
IMPORTANT
Cambridge Lower Secondary Science Stage 8 : Student's book>Chapter 4 - Elements, Compounds and Mixtures>Exercise 10>Q 5
The formula of magnesium chloride is MgCl2. A piece of magnesium chloride contains 400 chlorine atoms. How many magnesium atoms are there?
EASY
Lower Secondary Stage 8
IMPORTANT
Cambridge Lower Secondary Science Stage 8 : Student's book>Chapter 4 - Elements, Compounds and Mixtures>Exercise 11>Q 6
Describe how the properties of magnesium oxide are different to the elements it is made from.
EASY
Lower Secondary Stage 8
IMPORTANT
Cambridge Lower Secondary Science Stage 8 : Student's book>Chapter 4 - Elements, Compounds and Mixtures>Exercise 11>Q 7

A teacher heats together iron and sulphur. Iron sulphide is produced.

  • Name two elements mentioned.
EASY
Lower Secondary Stage 8
IMPORTANT
Cambridge Lower Secondary Science Stage 8 : Student's book>Chapter 4 - Elements, Compounds and Mixtures>Exercise 11>Q 7

A teacher heats together iron and sulphur. Iron sulphide is produced.

  • Name the compound.
EASY
Lower Secondary Stage 8
IMPORTANT
Cambridge Lower Secondary Science Stage 8 : Student's book>Chapter 4 - Elements, Compounds and Mixtures>Exercise 11>Q 7

A teacher heats together iron and sulphur. Iron sulphide is produced.

  • This is a chemical reaction. Explain what this means.
EASY
Lower Secondary Stage 8
IMPORTANT
Cambridge Lower Secondary Science Stage 8 : Student's book>Chapter 4 - Elements, Compounds and Mixtures>Identifying risks>Q A1

Samir is going to carry out a chemical reaction and make a compound called magnesium oxide. He plans to hold a strip of magnesium in a Bunsen burner flame until it gives out a bright white light and magnesium oxide is made. He will then put the magnesium oxide onto his desk, so he can observe it. This experiment could cause harm to Samir and the people around him.

  • Describe the hazards, and what Samir should do to reduce the chance of harm.
EASY
Lower Secondary Stage 8
IMPORTANT
Cambridge Lower Secondary Science Stage 8 : Student's book>Chapter 4 - Elements, Compounds and Mixtures>Exercise 13>Q 1
Describe the difference between a compound and a mixture.
EASY
Lower Secondary Stage 8
IMPORTANT
Cambridge Lower Secondary Science Stage 8 : Student's book>Chapter 4 - Elements, Compounds and Mixtures>Exercise 13>Q 2

Air contains the gases- nitrogen, oxygen, water vapour and carbon dioxide. For the following substances, write down whether it is an element, a compound or a mixture:

  • Air