What is a covalent bond?
2 marks · HardState what holds the atoms together in a covalent bond, and explain why a covalent bond only forms between certain atoms.
Work this out on paper, then compare with the answer and worked solution below. With a free account you can submit written answers for marking.
Show answer
Also accept: The atoms in a covalent bond are held together by the electrostatic attraction between the positively charged nuclei and the shared pair of electrons.; A covalent bond only forms between atoms that both need to gain electrons to achieve a full outer shell.
Common mistakes: Saying only 'sharing' without mentioning electrostatic attraction; Describing ionic bonding instead
Show mark scheme and worked solution
Marking points
B1 · 1 mark · States that atoms are held together by electrostatic attraction between nuclei and shared pair of electrons.
B2 · 1 mark · Explains covalent bonds only form when atoms need to gain electrons to get a full outer shell.
Worked solution
Atoms are held together in a covalent bond by the strong electrostatic attraction between the positively charged nuclei and the shared pair of electrons.
A covalent bond only forms between atoms that both need to gain electrons to achieve a full (noble gas) outer shell.