Hydrogen reacts with chlorine to form hydrogen chloride - Edexcel - GCSE Chemistry Combined Science - Question 5 - 2016 - Paper 1

To draw the dot-and-cross diagram for hydrogen chloride (HCl), follow these steps:

1. Identify the outer electrons:

   • Hydrogen has 1 outer electron and has an electronic configuration of 1.
   • Chlorine has 7 outer electrons and has an electronic configuration of 2.8.7.

2. Represent the electrons:

   • Use dots (•) to represent the outer electron of hydrogen.
   • Use crosses (×) to represent the outer electrons of chlorine.

3. Form the covalent bond:

   • Place the H and Cl together.
   • Draw the shared pair of electrons as one dot and one cross to show the covalent bond formed between them.

4. Final diagram representation:

   • The final dot-and-cross diagram will look as follows:

     H: • Cl: × × × × × × ×

     Here, the dot (•) from H is shared with one of the crosses (×) from Cl, indicating the formation of HCl.