Pearson Edexcel International GCSE (9–1) · CHEMISTRY · Section
What is a covalent bond?
19 practice questions
Practice questions
1–8 of 8 · Easy
Question 1
1 mark · Easy
Answer and see the solution →State the type of particles that are attracted to each other in a covalent bond.
Question 2
3 marks · Easy
Answer and see the solution →Chlorine exists as diatomic molecules ( Cl2 ).
(a)[2 marks]Draw a dot-and-cross diagram to show the covalent bonding in a molecule of chlorine (Cl2).
(b)[1 mark]How many electrons are shared between the two chlorine atoms?
Question 3
2 marks · Easy
Answer and see the solution →A phosphorus atom has 5 electrons in its outer shell. How many covalent bonds can it form in a molecule of phosphorus trichloride (PCl3)?
Question 4
2 marks · Easy
Answer and see the solution →Explain, using dot-and-cross diagrams, why a molecule of hydrogen fluoride (HF) contains only one covalent bond.
Question 5
3 marks · Easy
Answer and see the solution →Table 1 shows the number of outer shell electrons and covalent bonds formed by some elements.
Table 1. Covalent bonds and outer electrons Element Number of outer electrons Number of covalent bonds Hydrogen 1 ? Oxygen 6 ? Carbon 4 ? Nitrogen 5 ? Question 6
1 mark · Easy
Answer and see the solution →Draw a dot-and-cross diagram to show a single covalent bond between two bromine atoms in a Br2 molecule.
Question 7
3 marks · Easy
Answer and see the solution →A student claims: ‘All atoms in a covalent bond must supply one electron to the shared pair.’
(a)[2 marks]Is this statement always correct? Give a reason for your answer.
(b)[1 mark]State what a shared pair of electrons is called.
Question 8
2 marks · Easy
Answer and see the solution →Carbon dioxide (CO2) contains two double covalent bonds. How many shared electrons are present in the molecule in total?