Question

The masses of two isotopes of chlorine are $34.980$ and $36.978$. If the radius of the circular path in Bainbridge mass spectrograph corresponding to lighter is $5cm$, the distance between the spots on photographic plate marked by two isotopes will be

• A. $5.7cm$
• B. $0.57cm$
• C. $0.57mm$
• D. $0.57m$

Answer 1

The correct option is B $0.57cm$

Distance between the spots on photographic plate for two isotopes

$=2(r_2-r_1)=2\left(\frac{m_2-m_1}{m_1}\right)r_1=2\times \frac{36.978-34.980}{34.980}\times 0.05=0.57cm$