## Practice MCAT Question - Q51 - Answer!

**Two ions, X**

^{-}and Y^{-2}, are analyzed in a mass spectrometer. They travel at the same velocity. Ion X^{-}has twice the mass of ion Y^{-2}. Which statement is true?**A.**The radius of the path of X

^{-}will be half that of Y

^{-2}.

**B.**The radius of the path of X

^{-}will be twice that of Y

^{-2}.

**C.**The radius of the path of X

^{-}will be four times that of Y

^{-2}.

**D.**The radius of the path of X

^{-}will be the same as that of Y

^{-2}.

*The correct answer is (C). r = mv/qB becomes r*

_{x}= m_{x}/q_{x}= 2m_{y}/q_{x}= 2m_{y}/1 = 2m_{y}and r_{y}= m_{y}/q_{y}= m_{y}/2 = (1/2)m_{y}. Therefore, r_{x}is four times that of r_{y}.**Check The Sidebar For Another**

**Practice MCAT Question**

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