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General Chemistry

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Photoelectric Effect: Speed of Ejected Electron

CHEM-RXLVR6

The work function of magnesium metal is $5.90 \times {10}^{-19}J$.

If light of wavelength $\lambda = 250\ nm$ is shined on $Mg$, calculate the speed of the ejected electron in $\frac{m}{s}$.

The following values may be useful in your calculations:

  • $\text{Mass of electron} = 9.109 \times {10}^{-31} kg$

  • $c = 3.00 \times {10}^{8} \frac{m}{s}$

  • $h = 6.626 \times {10}^{-34} J \cdot s$

A

$2.05 \times {10}^{-19}$

B

$2.25 \times {10}^{11}$

C

$4.74 \times {10}^{5}$

D

$7.95 \times {10}^{-19}$