Atomic Specta Post-Module Assessment

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Gabe_Ek 1G
Posts: 62
Joined: Wed Sep 30, 2020 10:04 pm

Atomic Specta Post-Module Assessment

Postby Gabe_Ek 1G » Sun Oct 18, 2020 11:16 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. How much energy is required to remove an electron from one sodium atom?

Hi, I was able to get through this problem using the work function but got different answers when dividing by Avagrado's number. Why is it that we need to divide by Avagrado's number and when specifically do we need to?

Hazelle Gunawan 3G
Posts: 66
Joined: Wed Sep 30, 2020 9:52 pm

Re: Atomic Specta Post-Module Assessment

Postby Hazelle Gunawan 3G » Sun Oct 18, 2020 11:20 pm

Avogadro's number is the number of any object in a mole of that object, so you'd only need Avogadro's number when trying to find the number of moles of something.

Anthony_3C
Posts: 51
Joined: Wed Sep 30, 2020 10:00 pm

Re: Atomic Specta Post-Module Assessment

Postby Anthony_3C » Mon Oct 19, 2020 8:00 am

Since in this case the equations E = hv and E = KE + Φ come from quantum physics, they concern only values of one electron, not a mole.

Samudrala_Vaishnavi 3A
Posts: 61
Joined: Wed Sep 30, 2020 9:34 pm

Re: Atomic Specta Post-Module Assessment

Postby Samudrala_Vaishnavi 3A » Mon Oct 19, 2020 8:01 am

You wouldn't need to use Avogadro's number, in this case, considering "Sodium atom" just refers to the electron being removed from something and not the number of atoms. Also, we use Avogadro's number to find the number of moles through division and the number of atoms through multiplication. So, to find atoms, you wouldn't divide in general.


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