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Chlorine, Cl₂, is a simple molecular, covalent substance - Edexcel - GCSE Chemistry - Question 5 - 2016 - Paper 1
Question 5
Chlorine, Cl₂, is a simple molecular, covalent substance. The atoms in a molecule of chlorine are held together by a covalent bond. (i) Explain what is meant by th... show full transcript
Worked Solution & Example Answer:Chlorine, Cl₂, is a simple molecular, covalent substance - Edexcel - GCSE Chemistry - Question 5 - 2016 - Paper 1
Step 1
Explain what is meant by the term covalent bond.
Answer
A covalent bond is a type of chemical bond where two atoms share pairs of electrons. This sharing allows each atom to attain a full outer shell of electrons, achieving greater stability. In a covalent bond, the electrons are not transferred from one atom to another, as seen in ionic bonds, but rather are shared between the atoms involved.
Step 2
Draw the dot and cross diagram to show the bonding in a molecule of phosphorus trichloride, PCl₃.
Answer
In the dot and cross diagram for phosphorus trichloride (PCl₃), one phosphorus atom is in the center with three chlorine atoms surrounding it. The phosphorus atom has five outer electrons, which can be represented as dots. Each chlorine atom has seven outer electrons, out of which one electron will be represented as a cross. The diagram will thus illustrate:
Cl •
|
Cl • × • Cl
|
• P •
In this diagram, three pairs of electrons are shared between the phosphorus and chlorine atoms.
Step 3