Beryllium-9 is a stable isotope of beryllium - Edexcel - GCSE Physics - Question 4 - 2013 - Paper 1
Question 4
Beryllium-9 is a stable isotope of beryllium.
(i) State the meaning of the term stable.
(ii) Beryllium-9 has an atomic number of 4 and a mass number of 9. A nucleu... show full transcript
Worked Solution & Example Answer:Beryllium-9 is a stable isotope of beryllium - Edexcel - GCSE Physics - Question 4 - 2013 - Paper 1
Step 1
State the meaning of the term stable.
96%
114 rated
Only available for registered users.
Sign up now to view full answer, or log in if you already have an account!
Answer
The term 'stable' means that the isotope does not emit (ionising) radiation or is not radioactive. In other words, it does not undergo radioactive decay.
Step 2
Complete the sentence by putting a cross (X) in the box next to your answer. The number of neutrons in this nucleus is
99%
104 rated
Only available for registered users.
Sign up now to view full answer, or log in if you already have an account!
Answer
For Beryllium-9, the number of neutrons can be calculated using the formula:
extNumberofNeutrons=extMassNumber−extAtomicNumber
Thus:
9−4=5
Therefore, the correct answer is B (5).
Step 3
Which one of these symbols describes the nucleus of a different isotope of beryllium?
96%
101 rated
Only available for registered users.
Sign up now to view full answer, or log in if you already have an account!
Answer
The nucleus of a different isotope can be represented as either symbol provided, except for the isotope mentioned. Thus, put a cross (X) in the box next to the symbol that differs from 49Be. If provided symbols are:
A) 46Be
B) 48Be
C) 49Be
D) 59Be
The correct answer is either A, B or D depending on the actual symbols shown.
