A clean sample of magnesium metal is irradiated under vacuum with a 1 W laser. If the laser waveleng — Atomic Structure Chemistry Question
Question
A clean sample of magnesium metal is irradiated under vacuum with a 1 W laser. If the laser wavelength is 400 nm, nothing happens, but if the wavelength is 300 nm, then electrons with 45.6 kJ mol-1 of energy are ejected from the Mg surface. What happens if a 2 W laser is used instead?
A.✓ Correct
There is no change at 400 nm, but at 300 nm twice as many electrons are emitted at 45.6 kJ mol-1.
B.
There is no change at 400 nm, but at 300 nm, electrons are emitted at 91.2 kJ mol-1.
C.
There is no change at 400 nm, but at 300 nm, electrons are emitted at 444 kJ mol-1.
D.
At 400 nm, electrons are emitted at 245 kJ mol-1, while at 300 nm, electrons are emitted at 444 kJ mol-1.
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