How to find the kinetic energy of ejected electrons?

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elizabethrojas1G
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Joined: Fri Sep 25, 2015 3:00 am

How to find the kinetic energy of ejected electrons?

Postby elizabethrojas1G » Tue Sep 29, 2015 8:49 pm

Light hits a sodium metal surface and the velocity of the ejected electron is 6.61 x 105 m.s-1. The work function for sodium is 150.6 kJ.mol-1. What is the kinetic energy of the ejected electron?

I did see a previous post with this question but it wasn't clear to me how to actually solve it. If I used hv- work function = Ek would there be any way to find v or am I using the wrong equation?

Chem_Mod
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Re: How to find the kinetic energy of ejected electrons?

Postby Chem_Mod » Tue Sep 29, 2015 9:01 pm

Kinetic energy is calculated through the formula KE= 0.5 m*v2, where m is the mass, in this case the ejected electron mass, and v is the velocity which is given in the question.

elizabethrojas1G
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Re: How to find the kinetic energy of ejected electrons?

Postby elizabethrojas1G » Mon Oct 12, 2015 7:30 pm

thank you

Lauren Wong 3K
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Re: How to find the kinetic energy of ejected electrons?

Postby Lauren Wong 3K » Tue Sep 27, 2016 11:32 pm

How do you find the mass of the ejected electron?

Chem_Mod
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Re: How to find the kinetic energy of ejected electrons?

Postby Chem_Mod » Wed Sep 28, 2016 9:19 am

The mass of an electron is a constant, so it's given to you and it's always the same.


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