The element antimony (Sb) has at least 29 known isotopes - VCE - SSCE Chemistry - Question 7 - 2003 - Paper 1
Question 7
The element antimony (Sb) has at least 29 known isotopes. Only two of these are stable isotopes that occur naturally; the other 27 isotopes are radioactive and have ... show full transcript
Worked Solution & Example Answer:The element antimony (Sb) has at least 29 known isotopes - VCE - SSCE Chemistry - Question 7 - 2003 - Paper 1
Step 1
What operations occur in stages 1 and 3?
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Answer
Stage 1: The sample undergoes ionisation through introduction/vaporisation or electron bombardment.
Stage 3: The ions are subjected to magnetic and/or electric fields for deflection.
Step 2
How is ionisation achieved in stage 2?
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Ionisation is achieved through methods such as electron bombardment, where high-energy electrons collide with the sample atoms to produce positively charged ions.
Step 3
How is deflection achieved in stage 4?
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Deflection is achieved using a magnetic and/or electric field, which causes the charged ions to deviate from their paths based on their mass-to-charge ratio.
Step 4
What information can be obtained from a mass spectrometer about naturally occurring antimony?
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A mass spectrometer can provide information on the relative mass and abundance of each stable isotope of antimony, specific isotope ratios, and the natural isotopic distribution of antimony.
Step 5
From the data given, calculate the percentage abundance of each of the stable isotopes of naturally occurring antimony.
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Given that the relative atomic mass of naturally occurring antimony is 121.75, we can set up the equation:
[ 121.75 = (x)(120.903) + (1-x)(122.9041) ]
Solving for (x), where (x) is the abundance of (^{121}Sb):
Let abundance of (^{121}Sb) be (x) and (^{123}Sb) be (1-x).
Solve:
[ 121.75 = 120.903x + 122.9041(1-x) ]
Rearranging gives us:
[ x = 0.423 \Rightarrow 42.3% \text{ for }^{121}Sb ]
Therefore, percentage abundance of (^{123}Sb) is (57.7%) since (1 - x = 1 - 0.423 = 0.577).
Step 6
Give the symbol and charge of the most common antimony ion that would be detected using mass spectrometry.
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The most common antimony ion detected using mass spectrometry is (Sb^{3+}).
Step 7
How many neutrons are there in the nucleus of the \(^{121}Sb\) isotope?
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The number of neutrons in the (^{121}Sb) isotope is calculated by subtracting the atomic number (51) from the mass number (121):
[ Neutrons = 121 - 51 = 70 ]
Step 8
Give the symbol of the atoms produced from the decay process of each of the given radioactive isotopes.
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i. For (^{125}Sb): (^{125}Te + \beta^-
ii. For (^{123}Sb): (^{123}Sn + e^+)
