A mass spectrometer uses a velocity selector where a uniform magnetic field B1=0.15 TB_1 = 0.15\text{ T}B1=0.15 T and a uniform electric field E=3.0×104 V m−1E = 3.0 \times 10^4\text{ V m}^{-1}E=3.0×104 V m−1 act at right angles to select positive ions of a specific speed. The selected singly-charged ions (q=+1.6×10−19 Cq = +1.6 \times 10^{-19}\text{ C}q=+1.6×10−19 C) then enter a deflection chamber containing a uniform magnetic field B2=0.25 TB_2 = 0.25\text{ T}B2=0.25 T perpendicular to their velocity, where they describe a circular path of radius r=16.6 cmr = 16.6\text{ cm}r=16.6 cm.
What is the mass of these ions?
2.0×10−26 kg2.0 \times 10^{-26}\text{ kg}2.0×10−26 kg
3.3×10−26 kg3.3 \times 10^{-26}\text{ kg}3.3×10−26 kg
3.3×10−24 kg3.3 \times 10^{-24}\text{ kg}3.3×10−24 kg
1.5×10−24 kg1.5 \times 10^{-24}\text{ kg}1.5×10−24 kg