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### Clarification on the Work Equation? (Photoelectric Effect)

Posted: **Thu Apr 12, 2018 3:37 pm**

by **KC Navarro_1H**

In the Photoelectric Effect module video, I was sort of confused as to how the work equation fits in with wavelength and frequency.

Specifically,

hv - Φ (Work Equation) = 1/2 (m_e- v_e-)^2 (Threshold Energy)

It might've been typed weirdly in the video, but how is this equation broken down?

### Re: Clarification on the Work Equation? (Photoelectric Effect) [ENDORSED]

Posted: **Thu Apr 12, 2018 5:46 pm**

by **Chem_Mod**

I will discuss this in class tomorrow (Friday) in detail.

Note: The "work function" is a measured value (not an equation). The work function is the (measured) energy required to remove an electron from a metal surface.

The three energy terms are:

1. Energy of incoming photon (that interacts with the metal surface).

2. Energy required to remove an electron from the metal surface.

3. Excess energy the ejected electron may have.

The balance of the above three energy terms can be written as:

1 - 2 = 3

Another way to think of it: 1 = 2 + 3 (conservation of energy)

### Re: Clarification on the Work Equation? (Photoelectric Effect)

Posted: **Fri Apr 13, 2018 11:22 am**

by **KC Navarro_1H**

Chem_Mod wrote:I will discuss this in class tomorrow (Friday) in detail.

Note: The "work function" is a measured value (not an equation). The work function is the (measured) energy required to remove an electron from a metal surface.

The three energy terms are:

1. Energy of incoming photon (that interacts with the metal surface).

2. Energy required to remove an electron from the metal surface.

3. Excess energy the ejected electron may have.

The balance of the above three energy terms can be written as:

1 - 2 = 3

Another way to think of it: 1 = 2 + 3 (conservation of energy)

Thank you! Then the work function is subtracted from Planck's Constant x Frequency to get the result of 1/2 m_e- v_e- (and solve for whatever variable you need)?