## Threshold Energies

$c=\lambda v$

Nathan Mariano 2G
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Joined: Fri Sep 28, 2018 12:29 am

### Threshold Energies

Why do different metals have different threshold energies?

605168557
Posts: 65
Joined: Fri Sep 28, 2018 12:18 am

### Re: Threshold Energies

Depending on the metal's properties, it is easier to remove electrons from some metals than others. The variations in threshold energies are dependent on the metal's work function. The smaller the work function (minimum amount of energy required), the lower the frequency.

Raj_Bains_2C
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### Re: Threshold Energies

Different metals have different threshold energies because they have a different number of protons, electrons, and energy levels. If the metal has many protons and electrons, there will be more energy levels, resulting in the electrons being further away from the nucleus. These negatively charged electrons experience less of a pull from the positively charged nucleus and therefore, less energy will be required to take the electron away. Similarly, if there are less electrons and protons, they will be closer together and will have a stronger pull on each other. In this case, more energy will be required to take the electron away.

Mona Lee 4L
Posts: 60
Joined: Fri Sep 28, 2018 12:16 am

### Re: Threshold Energies

Different metals have different threshold energies depending on the nucleic pull on electrons. There are many factors that affect the nucleic pull. ie: electrons far away from the protons will be "shielded" from the nucleic force and as a result, easier to remove.

Henry Dudley 1G
Posts: 61
Joined: Fri Sep 28, 2018 12:16 am

### Re: Threshold Energies

Raj_Bains_3C wrote:Different metals have different threshold energies because they have a different number of protons, electrons, and energy levels. If the metal has many protons and electrons, there will be more energy levels, resulting in the electrons being further away from the nucleus. These negatively charged electrons experience less of a pull from the positively charged nucleus and therefore, less energy will be required to take the electron away. Similarly, if there are less electrons and protons, they will be closer together and will have a stronger pull on each other. In this case, more energy will be required to take the electron away.

So does this mean that elements higher on the periodic table have a lower threshold energy?

Raj_Bains_2C
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### Re: Threshold Energies

Henry Dudley 1I wrote:
Raj_Bains_3C wrote:Different metals have different threshold energies because they have a different number of protons, electrons, and energy levels. If the metal has many protons and electrons, there will be more energy levels, resulting in the electrons being further away from the nucleus. These negatively charged electrons experience less of a pull from the positively charged nucleus and therefore, less energy will be required to take the electron away. Similarly, if there are less electrons and protons, they will be closer together and will have a stronger pull on each other. In this case, more energy will be required to take the electron away.

So does this mean that elements higher on the periodic table have a lower threshold energy?

I'm sorry. Threshold energy is the energy required for two elements to fuse and create a reaction. I believe this thread means to discuss ionization energy, which is the energy required to remove a valence election from an atom. My explanation above answers why different metals have different ionization energies. To answer your question, elements higher on the periodic table actually have higher ionization energies because the electrons are closer to the nucleus. Therefore, the attraction is stronger and more energy is required to remove the outer electron.