(a) Figure 8 shows the symbol for the nucleus of an atom of strontium-90 - Edexcel - GCSE Physics - Question 5 - 2020 - Paper 1
Question 5
(a) Figure 8 shows the symbol for the nucleus of an atom of strontium-90.
(i) How many protons are in the nucleus of an atom of strontium-90?
(1)
A 38
B 52
C 9... show full transcript
Worked Solution & Example Answer:(a) Figure 8 shows the symbol for the nucleus of an atom of strontium-90 - Edexcel - GCSE Physics - Question 5 - 2020 - Paper 1
Step 1
How many protons are in the nucleus of an atom of strontium-90?
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Answer
The number of protons in an atom is represented by the atomic number, which is 38 for strontium-90. Therefore, the answer is A: 38.
Step 2
How many neutrons are in the nucleus of an atom of strontium-90?
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Answer
To find the number of neutrons, subtract the atomic number from the mass number. Strontium-90 has a mass number of 90 and an atomic number of 38:
Neutrons=Mass number−Atomic number=90−38=52
Thus, the answer is B: 52.
Step 3
Complete the table in Figure 9.
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Answer
At time 0 years, the mass is 1600 g, and at 29 years, the mass has decayed to 400 g. This shows a decrease in mass due to the half-life of the substance.
Step 4
State the scientific name for the radioactivity detector shown in Figure 10.
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Answer
The scientific name for the radioactivity detector shown in Figure 10 is a geiger counter.
