Pearson Edexcel International GCSE (9–1) · CHEMISTRY · Section
What is a covalent bond?
19 practice questions
Practice questions
1–3 of 3 · Hard
Question 1
2 marks · Hard
Answer and see the solution →State what holds the atoms together in a covalent bond, and explain why a covalent bond only forms between certain atoms.
Question 2
5 marks · Hard
Answer and see the solution →Boron trifluoride (BF) is a covalent compound. Answer the following questions about its bonding.
(a)[1 mark]How many electrons are in the outer shell of a boron atom and of a fluorine atom?
(b)[2 marks]Draw a dot-and-cross diagram to show the covalent bonding in a molecule of BF. Use dots (•) for boron’s electrons and crosses (×) for fluorine’s electrons.
(c)[2 marks]Explain, using your diagram, why the central boron atom in BF does not have a full octet in its outer shell.
Question 3
2 marks · Hard
Answer and see the solution →Explain what a covalent bond is and describe how the sharing of electrons holds the bonded atoms together.