6.2.2

Dot-and-Cross Diagrams

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Dot-and-Cross Diagrams

Dot-and-cross diagrams can be used to represent covalent bonds and to show the sharing of electron pairs.

Illustrative background for Chlorine (Cl<sub>2</sub>)Illustrative background for Chlorine (Cl<sub>2</sub>) ?? "content

Chlorine (Cl2)

  • Each chlorine (Cl) atom begins with 7 electrons in its outer shell.
  • By sharing 1 pair of electrons in a single covalent bond, each Cl atom obtains a full outer shell with 8 electrons.
Illustrative background for Water (H<sub>2</sub>O)Illustrative background for Water (H<sub>2</sub>O) ?? "content

Water (H2O)

  • Because oxygen has 6 electrons in its outer shell, it needs to have 2 extra electrons shared with it to get a full outer electron shell.
  • To do this, it forms a single covalent bond with 2 hydrogen atoms.
Illustrative background for Double and triple bondsIllustrative background for Double and triple bonds ?? "content

Double and triple bonds

  • The earlier examples show single covalent bonds (1 shared pair of electrons between atoms), but it is also possible to form double (2 shared pairs) and even triple covalent bonds (3 shared pairs).
  • Double and triple bonds are normally stronger and require more energy to break.
Illustrative background for Oxygen (O<sub>2</sub>)Illustrative background for Oxygen (O<sub>2</sub>) ?? "content

Oxygen (O2)

  • Each oxygen needs 2 electrons to get a full outer shell.
  • Therefore, each oxygen atom shares 2 electrons with the other, leaving 2 pairs of electrons in the shared space between the atoms.
  • This is an example of a double covalent bond.

Jump to other topics

1States of Matter

2Elements, Compounds & Mixtures

3Atomic Structure

4The Periodic Table

5Chemical Formulae, Equations & Calculations

6Bonding

7Electrolysis

8Groups of the Periodic Table

9The Atmosphere

10Reactivity Series

11Metal Extraction

12Acids & Alkalis

13Chemical Tests

14Physical Chemistry

15Organic Chemistry

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