Ionization Energies Of Noble Gases

• chikis
In summary, the conversation discussed the concept of atomic radii and how it relates to the noble gases having the highest ionization energies in each period. There was a discussion about the definition of atomic radii and how different measurements can result in different values. Ultimately, it was agreed upon that under most definitions, the noble gases actually have the smallest atomic radii in their respective periods, contradicting the initial statement that they have the highest ionization energies due to their large atomic radii.
chikis

Homework Statement

I was going through my past question and answer, I then came across this:
"The noble gases have the highest ionization energies in each period".
I then wondered why and how the above statement is a reality. How can the above statement be true when the noble gases have large atomic radi?

Homework Equations

No equation is involved.

The Attempt at a Solution

I know that Ionization energy, is the energy required to remove the outermost electron from a gasous atom.
If you say that the noble gases has the highest Ionization energies, how true is that when you know that the noble gases have a relatively large atomic radius?
I believe that the noble gases should have the lowest ionization energy since they have large atomic radius. This (lowest ionization energy) is possible because the larger the atomic radius the farer the distance of the outermost electron from the attraction of the nucleuos, thereby making it easier for outermost electron to escape. In such circustance, the outermost electron will leave with a very small energy.
From my statement above, I have it that the noble gases have the lowest and not the highest ionization energy.
If you the person viewing this my thread has a contrary view to mine on this concept on discusion feel free to share your own opinion. Let's see how we can collectively solve this problem.

You are forgetting that the noble gases are (generally) inert. They all have a full outer shell of electrons, which makes it very difficult to remove any electrons.

tal444 said:
You are forgetting that the noble gases are (generally) inert. They all have a full outer shell of electrons, which makes it very difficult to remove any electrons.

So is that the reason why they should have high ionization energies?

And the fact that that they have the highest Zeff within each period.

chemisttree said:
And the fact that that they have the highest Zeff within each period.

What is the meaning of this "Zeff"?

Did any of you agree with me that noble gases have largd atomic radi?

Borek said:

For now, I understand from the link you pasted in that "Zeff" stands for effective nuclear charge. But with time, I will post in what I found complicating with the link. Thank you.

Redbelly98 said:
I have open the link which you pasted in. The link contained information concerning trends in periodic table, like ionization enegy, atomic radi, electron affinity, electronegative and the rest.
The issue is that my question has not been answered. My question is this, did any of you agree with me that noble gases have large atomic radius in each period?
Watch the link below and see for your self why am asking that question. In that link, you will see that in each period you go, the noble gases have large atomic radi which is equal in size to those of akali metals. So you now see why am asking that question with much zeal and expecting an answer.

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From http://en.wikipedia.org/wiki/Periodi...#Atomic_radius: "The atomic radius tends to decrease as one progresses across a period from left to right". This quote clearly states that atomic radii DECREASES from left to right. As noble gases are on the very right, this would mean that noble gases actually have the SMALLEST radii in their respective periods.

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chikis said:

Data for Rn shows that the table can't be trusted.

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Borek said:
Data for Rn shows that the table can't be trusted.

What do you mean by Rn?

tal444 said:

Thank you for reminding me.

chikis said:
So you now see why am asking that question with much zeal and expecting an answer.

Much zeal?

chikis said:
I have open the link which you pasted in. The link contained information concerning trends in periodic table, like ionization enegy, atomic radi, electron affinity, electronegative and the rest.
The issue is that my question has not been answered. My question is this, did any of you agree with me that noble gases have large atomic radius in each period?
Watch the link below and see for your self why am asking that question. In that link, you will see that in each period you go, the noble gases have large atomic radi which is equal in size to those of akali metals. So you now see why am asking that question with much zeal and expecting an answer.

Okay, that is a puzzling image. But I have found an explanation in the page where that image is posted:

There is a lot of information there, about different ways that "atomic radii" can be defined. Scroll down to the "Table of Atomic Radii" on that page, which lists radii for several different definitions of that term. Under most definitions, noble gases have the smallest radius in their respective row of the periodic table. Only for the "van der Waals radius" is the noble gas radius larger as shown in your figure. I'm a little puzzled as to why they chose that one to use in their chart at the very top of their page, but they did.

Most importantly, look at the definitions of radii that use either (1) an isolated atom, or (2) an atom covalently bonded to another atom -- for these definitions, the noble gases are the smallest in their respective rows.

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chemisttree said:
And the fact that that they have the highest Zeff within each period.

from the link you pasted in, I saw that after calculating Zeff for Na cation or F anion and neutral Ne, the aticle stated it clearly that Na cation has the highest Zeff and thus the smallest atomic radius.
But we are not talking about cation or anions here.

Redbelly98 said:
Okay, that is a puzzling image. But I have found an explanation in the page where that image is posted:

There is a lot of information there, about different ways that "atomic radii" can be defined. Scroll down to the "Table of Atomic Radii" on that page, which lists radii for several different definitions of that term. Under most definitions, noble gases have the smallest radius in their respective row of the periodic table. Only for the "van der Waals radius" is the noble gas radius larger as shown in your figure. I'm a little puzzled as to why they chose that one to use in their chart at the very top of their page, but they did.

Most importantly, look at the definitions of radii that use either (1) an isolated atom, or (2) an atom covalently bonded to another atom -- for these definitions, the noble gases are the smallest in their respective rows.

You are correct. Am beginning to come to my senses. Initialy whenever the word radi is mentioned, what comes to my mind is nothing but atomic radi. I never knew there are diffrences. I used to think that ionic, vandawal, atomic and convalent radi are all the same. But in this thread am discussing atomic radi. All the same, I say thank you for the awareness.
I now accept that atomic radi decreases left to right across a period thus the nobles gases being at the extrem right of each row should have the smallest atomic radi.

1. What is ionization energy?

Ionization energy is the amount of energy required to remove an electron from an atom or molecule. This is typically measured in units of kilojoules per mole (kJ/mol) or electron volts (eV).

2. Why are noble gases used to study ionization energies?

Noble gases, also known as inert gases, have a full outer electron shell, making them stable and resistant to chemical reactions. This allows for more accurate measurements of ionization energies without interference from other chemical reactions.

3. How does ionization energy vary among the noble gases?

The ionization energy generally increases as you move across the noble gas group in the periodic table. This is due to the increasing number of protons in the nucleus, which leads to a stronger attraction for the electrons in the outer shell.

4. What are some practical applications of studying ionization energies of noble gases?

The study of ionization energies can provide valuable information about the electronic structure and reactivity of atoms and molecules. This can be applied in fields such as materials science, environmental science, and even in the development of new technologies.

5. How can ionization energies be used to identify unknown elements?

Each element has a unique set of ionization energies, which can be used as a form of fingerprinting to identify unknown elements. By comparing the ionization energy values of an unknown element to known elements, scientists can determine its identity and properties.

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