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Magnesium oxide nanoparticles can kill bacteria - AQA - GCSE Chemistry - Question 6 - 2014 - Paper 1
Question 6
Magnesium oxide nanoparticles can kill bacteria. Figure 6 shows the percentage of bacteria killed by different sized nanoparticles. 6 (a) (i) Give two conclusions ... show full transcript
Worked Solution & Example Answer:Magnesium oxide nanoparticles can kill bacteria - AQA - GCSE Chemistry - Question 6 - 2014 - Paper 1
Step 1
Give two conclusions that can be made from Figure 6.
Answer
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As the size of the nanoparticles increases beyond 8.5 nm, the effectiveness of killing both Type 1 and Type 2 bacteria decreases, indicating a larger size correlates to lower bacterial lethality.
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The relationship between the size of nanoparticles and the percentage of bacteria killed shows that Type 1 bacteria are more susceptible to these nanoparticles at all examined sizes compared to Type 2 bacteria.
Step 2
Would collecting and plotting data for more sizes of nanoparticles improve the conclusions?
Answer
Yes, additional data points would help confirm the existing patterns observed, providing a clearer trend of the relationship between nanoparticle size and bacterial lethality. This would reduce the risk of anomalies affecting the conclusions drawn from the current dataset.
Step 3
Describe, as fully as you can, what happens when magnesium atoms react with oxygen atoms to produce magnesium oxide.
Answer
When magnesium atoms react with oxygen, each magnesium atom loses two electrons to form a Mg²⁺ ion. Simultaneously, each oxygen atom gains two electrons to form an O²⁻ ion. This transfer of electrons leads to the formation of ionic bonds between the positively charged magnesium ions and negatively charged oxide ions, resulting in the formation of magnesium oxide (MgO). This compound typically exhibits a crystalline structure, characterized by its stable ionic lattice that contributes to its high melting point and overall stability.