Step-by-step explanation:
A single covalent bond is made up of 2 electrons (one from each atom). It is represented with a single line.
Each line is represented as one dot and one cross (. x)
A double covalent bond is made up of 4 electrons (2 from each atom). It is represented using 2 lines. As dot and cross, it will be represented with 2 dots and 2 crosses.
A triple covalent bond is made up of 6 electrons (3 from each atom). It is represented using 3 lines. As dot and cross, it will be represented with 3 dots and 3 crosses.
Know the number of electron (s) needed by the atom to have noble gas configuration / stable (Key: You should know your electron arrangement / group number / Refer to table provided)*.
Groups and the number of electrons needed for atoms to have noble gas configuration or have full outer shell(s).
Group 4: Four (4) electrons needed for the outer shell to become full / noble gas configuration;
Group 5: Three (3) electrons needed by the atom to have a full outer shell / noble gas configuration;
Group 6: Two (2) electrons needed
Group 7: One (1) electron needed