Periodic Trend Exceptions

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AChoudhry_1L
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Joined: Sat Sep 07, 2019 12:17 am

Periodic Trend Exceptions

Postby AChoudhry_1L » Tue Oct 22, 2019 9:57 am

In lecture, we went over the trends shown in the periodic table, however, Dr. Lavelle mentioned that there were a few exceptions to these trends. Which ones do we have to know and why do they not follow the trends?

Chris Tai 1B
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Re: Periodic Trend Exceptions

Postby Chris Tai 1B » Tue Oct 22, 2019 11:09 am

One such exception is the ionization energy for oxygen. Because atoms tend to prefer to have either full or half full shells, oxygen will prefer to have 3 electrons in the p orbital instead of having only one pair and two unpaired electrons. Conversely, Nitrogen is somewhat content with its half full p shell, and Fluorine does not want to give up electrons because of it's higher electronegativity, and hence oxygen's ionization energy is somewhat lower.
Instead of the ionization energy increasing from Nitrogen to Oxygen, it decreases and then increases again to Fluorine.

Cynthia Gong 1L
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Joined: Fri Aug 09, 2019 12:15 am

Re: Periodic Trend Exceptions

Postby Cynthia Gong 1L » Tue Oct 22, 2019 10:35 pm

Another exception is electron affinity for noble gases. Electron affinity increases across a period until you get to a noble gas, because when an electron is added to the full shell of a noble gas, the stability of the atom becomes destroyed.

Victoria Otuya 4F
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Joined: Wed Sep 18, 2019 12:21 am

Re: Periodic Trend Exceptions

Postby Victoria Otuya 4F » Tue Oct 22, 2019 11:08 pm

The two exceptions that Lavelle talked through in Lecture was Copper and Chromium. There might be more underneath those elements.

alicechien_4F
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Re: Periodic Trend Exceptions

Postby alicechien_4F » Thu Oct 24, 2019 1:16 pm

Along with Cr and Cu, all of the elements that are in the same group underneath those elements exhibit the same exception for their electron configuration.

705198479
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Re: Periodic Trend Exceptions

Postby 705198479 » Thu Oct 24, 2019 1:48 pm

can someone explain to me what trends are?

MinuChoi
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Joined: Wed Sep 18, 2019 12:15 am

Re: Periodic Trend Exceptions

Postby MinuChoi » Thu Oct 24, 2019 2:22 pm

can someone explain to me what trends are?


The periodic trends are traits of atoms that change based on the element and can be visualized on the periodic table.
For example: atomic radius (basically how big the atoms are). If you put every element's atomic radius on a periodic table, that value will be larger as you look down a group or left in a row on the periodic table.

Lizette Noriega 1H
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Joined: Wed Sep 18, 2019 12:15 am

Re: Periodic Trend Exceptions

Postby Lizette Noriega 1H » Thu Oct 24, 2019 5:18 pm

I know there is a trend for valence electrons which is to look at the column number to determine the number of valence electrons found in a certain element. Although, this only applies to the s and p blocks.


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