Photo AI
One isotope of the element potassium is potassium-40 - Edexcel - GCSE Physics - Question 4 - 2015 - Paper 1
Question 4
One isotope of the element potassium is potassium-40. A nucleus of potassium-40 is represented by $$\frac{40}{19}K$$ (i) Complete the sentence by putting a cross ... show full transcript
Worked Solution & Example Answer:One isotope of the element potassium is potassium-40 - Edexcel - GCSE Physics - Question 4 - 2015 - Paper 1
Step 1
Step 2
Which of these symbols is correct for the nucleus of a different isotope of potassium?
Answer
To identify a different isotope, we look for a symbol with the same atomic number (19) but a different mass number. The correct representation is:
,
indicating that this is potassium-40 with a different atomic structure. Thus, the answer is B.
Step 3
Describe what information this gives about the isotope potassium-40.
Answer
The fact that potassium-40 can emit gamma radiation while transforming into argon-40 indicates that potassium-40 is radioactive. This process suggests the following points:
- Radioactive nature: Potassium-40 undergoes radioactive decay, leading to the emission of gamma radiation.
- Transformation: The process of decay shows that potassium-40 is not stable and changes over time into another element (argon-40).
- Long-lived isotope: This transformation implies that potassium-40 has a half-life, remaining present for significant periods before changing into argon-40.