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Glass is made from silicon dioxide - AQA - GCSE Chemistry - Question 7 - 2014 - Paper 1
Question 7
Glass is made from silicon dioxide. Silicon dioxide has a very high melting point. Other substances are added to silicon dioxide to make glass. Glass melts at a low... show full transcript
Worked Solution & Example Answer:Glass is made from silicon dioxide - AQA - GCSE Chemistry - Question 7 - 2014 - Paper 1
Step 1
Suggest why glass melts at a lower temperature than silicon dioxide.
Answer
The addition of other substances to silicon dioxide creates weaker bonds in the overall structure. This reduction in bond strength allows the glass to melt at lower temperatures compared to silicon dioxide, which has stronger, more stable bonds.
Step 3
Complete the diagram to show the outer electrons in an oxygen molecule (O2).
Answer
In the diagram, each oxygen atom will have two bonding pairs (shared electrons) represented by lines or dots between them, and two lone pairs of electrons on each oxygen atom, drawn as pairs of dots in the outer regions.
Step 4
Describe the structure of a metal.
Answer
Metals have a lattice structure consisting of positively charged ions arranged in a regular pattern. The layers of ions are closely packed, with free or delocalized electrons moving throughout the structure. This arrangement allows metals to conduct electricity and heat efficiently, as well as giving them malleability and ductility.