Questions tagged [ionization-energy]
The ionization energy of an atom or molecule describes the minimum amount of energy required to remove an electron from the atom or molecule in the gaseous state. Do not confuse with [electron-affinity].
164
questions
1
vote
0
answers
59
views
Is ionization energy enthalpy change?
In physics, we learn how to calculate the ionization energy of a hydrogen atom using the Bohr model. The result is the following equation:
$$
E = - \frac{1}{n^2} \frac{Z^2e^2}{2a_0} = - \frac{Z^2 R_H}{...
- 123
0
votes
0
answers
60
views
If the effective nuclear charge of Beryllium(Be) is less than Sodium's(Na), how is the ionization energy of Be higher than Na?
According to Slater's rules the effective nuclear charge of Beryllium and Sodium is 1.95 and 2.20 respectively.
That means that the outermost electron of Na feels a stronger attraction from the ...
0
votes
1
answer
69
views
What is the difference between exciting an electron to a higher bound state and removing it completely (ionizing the atom)? [closed]
We are reviewing quantum mechanics and orbitals in my class and I'm confused about the energies to move an electron to an excited state vs. remove it from an atom.
Even though the electron on a H atom ...
- 11
1
vote
2
answers
499
views
Reason for exceptions in I.E. trend in group 13
In general, we would expect IE to decrease down a group. This is because atomic radius increases $\implies$ valence electrons are further from nucleus $\implies$ less effective nuclear attraction on ...
- 317
0
votes
0
answers
26
views
Why does Cl- have a higher ionization energy than F-? [duplicate]
I know that F has a higher ionization energy than Cl as the outermost electron is closer to the nucleus. By the same logic shouldn't F- also have a higher ionization energy than Cl-?
- 1
-2
votes
2
answers
82
views
Are there any monocations with negative electron affinities known?
It is known that most dianions are unbound per se, i.e. that the corresponding monoanions have negative electron affinities, and the "dianions" we see in e.g. metal oxides can exist as such ...
- 677
0
votes
0
answers
30
views
Theoretical extent of exactness of IE/BG of Kohn-Sham DFT with exact XC functional
It is known that Kohn-Sham DFT with an exact XC functional theoretically exactly captures (the ionisation potential)(resp. the band gap) as (the HOMO energy level negated)(resp. the difference between ...
- 677
1
vote
2
answers
204
views
Why is orbital energy not the mean between ionization energy and electron affinity when the orbital has two electrons?
In this question it is asked why ferrocene is colored when the HOMO-LUMO gap seems to be beyond the visible light range. I tried to answer that orbital energies change with electronic transitions and ...
- 48.6k
-3
votes
1
answer
97
views
Confusion regarding 1st and 2nd electron gain enthalpy
$\ce{O}$ has the 1st electron gain enthalpy $\pu{-141 kJ mol-1}$. $-ve$ value implies that energy is released when electron is added to an isolated atom. This also means that if $\pu{141 kJ}$ energy ...
- 103
1
vote
1
answer
108
views
Why does the Shielding Constant of Orbitals in Slater's rule get higher, the further away we are from the electron we are considering?
My text material says:
$\mathrm{Z_{eff}= Z-S}$ where $\mathrm{Z_{eff}}$ is the effective nuclear change on that specified electron; $\mathrm{Z}$ is the atomic number and $\mathrm{S}$ is the shielding ...
- 13
2
votes
0
answers
117
views
How did this paper mathematically express field driven water autoionization?
I recently read a paper on using an electric field to drive water autoionizaton. I'm trying to figure out how to use the Laplace equation on pg 9; 4th paragraph; to solve for voltage. I'm also ...
- 31
-2
votes
1
answer
179
views
How to calculate ionization energy of an atom provided energy of the electron at ground state? [closed]
It is given that in ground state the energy of electron in hydrogen atom is $-2.18\times10^{-18}\mathrm{J}$. I'm required to calculate the Ionization Energy in kJ/mol
Question for reference:
At ...
- 1
0
votes
1
answer
118
views
The higher energy to transform Cu(s)/Cu^2+(aq) is not balanced by its hydration enthalpy
The book says that "the higher energy to transform Cu(s)/Cu^2+(aq) is not balanced by its hydration enthalpy". I also read that when we add energy of sublimation and ionization energy , ...
1
vote
1
answer
491
views
How to know the group number from the ionization energy?
The successive ionization energy of the first four electrons of a representative element are $\pu{738.1 kJ/mol}$, $\pu{1450 kJ/mol}$, $\pu{7730 kJ/mol}$ and $\pu{10500 kJ/mol}$. Characterize the ...
- 225
0
votes
3
answers
103
views
Do Ions with less stability have less energy of ionization than those who are stable?
Problem. I've come up with the strange example of the third energy of ionization of both $\pu{Mg}$ and $\pu{Al}$, the standard logic that is to be applied on any problem of "which element has ...
- 135
0
votes
0
answers
83
views
The necessary energy required to ionize 1g of potasium in its fundamental state if the ionization energy is given
The energy of ionization of the potassium is $\pu{6.94\cdot 10^{-19} J/atom}.$ Find the necessary energy to ionize $\pu{1 g}$ of potasium that is found on its fundamental state.
Attempt. I really ...
- 135
2
votes
0
answers
28
views
What is the reaction steps taken when producing auroral forcing?
As described in here:
https://www.nasa.gov/feature/goddard/2018/sounding-rocket-mission-will-trace-auroral-winds
A mixture of Trimethylaluminium, Barium and Strontium reacts and ionize in the upper ...
- 689
1
vote
1
answer
316
views
Why does increasing subshell cause ionization energy to decrease?
I know that increasing subshell decreases ionization energy; for example, going from Beryllium to Boron. I do not understand why this is.
The answer my textbook (Chemistry 2e on OpenStax) gives is ...
5
votes
1
answer
2k
views
Why does magnesium have a greater ionization energy than lithium?
I'm a high school student and I'm learning about ionization energy and atomic radius of elements. I want to compare the ionization energy of lithium and magnesium.
Here is the information provided in ...
- 281
6
votes
0
answers
78
views
How are 2nd, 3rd, etc. ionization energies measured?
I am learning about ionization energies and I understand roughly how the first ionization energy can be measured. But how are the subsequent energies measured?
For the 1st ionization energy the ...
- 699
-3
votes
1
answer
133
views
Relation between common ion effect and the temperature of the solution [closed]
Adding extra Na+ in a saturated NaCl/water solution decreases the solubility of NaCl. How does this exactly happen? AFAIK, the solubility of a solid only decreases with the temperature of the solution....
-1
votes
1
answer
57
views
Can ions of a pure substance be obtained in only gaseous form? [closed]
I was studying mass spectrometry where I learned that the sample is first vaporized before ionization. And ions are formed in gaseous from in an ionization chamber.
Why is there need of vapourizing ...
- 29
0
votes
0
answers
30
views
First ionization energy and electron gain enthalpy of dihydrogen / stability comparison of dihydrogen ions [duplicate]
Subset of: How can antibonding orbitals be more antibonding than bonding orbitals are bonding?
Stability of $\ce{H2^{-}}<\ce{H2^{+}}<\ce{H2}$
Stability of $\ce{N2^{-}}<\ce{N2^{+}}<\ce{N2}...
- 804
2
votes
1
answer
459
views
Why is a sodium chloride molecule stable?
The ionization energy of sodium is $\pu{5.139eV}$. This is the energy absorbed when a neutral sodium atom is stripped of its outermost electron. The electron affinity of chlorine is $\pu{3.62eV}$. ...
- 239
-2
votes
1
answer
65
views
Predict the valence configuration of this element using the first five ionization energies [closed]
If the first five ionization energies of an element are, respectively: $\pu{1.09 kJ/mol}$, $\pu{2.35 kJ/mol}$, $\pu{4.62 kJ/mol}$, $\pu{6.22 kJ/mol}$ and $\pu{37.83 kJ/mol}$, to which group of the ...
- 9
2
votes
1
answer
856
views
Why does the ionization enthalpy of elements across a period not follow a regular pattern while the atomic size always decreases?
First of all, I would like to mention that I am only talking about elements that aren't from the d or f blocks.
In order to further elaborate on my question, I would like to take the third period as ...
15
votes
1
answer
2k
views
Why doesn't ionization energy decrease from O to F or F to Ne?
I know that in general, the first ionization energy increases across a period due to increasing nuclear charge, reasonably constant shielding & decreasing atomic radius.
From N to O, however, the ...
- 553
1
vote
1
answer
321
views
What is the 'electronic energy', in units of 'negative' hartrees, of a molecule?
On a NIST (National Institute for Standards and Technology) page on the molecular details of water and it's various isotopologues, I came across this:
Electronic energy: -76.4089547246 hartree
There ...
- 1,775
0
votes
1
answer
613
views
As electron energy increases, does ionisation energy decrease?
"Electrons are negatively charged, therefore, two electrons repel each other. When electrons are paired in a 3p orbital there is electron pair repulsion which causes the energy of the electrons ...
- 11
2
votes
0
answers
33
views
What explains the trend of ionization potential in coinage metals? [duplicate]
The expected pattern for ionization potential is
$$\ce{Cu} > \ce{Ag} > \ce{Au},$$
but the observed patter or experimental value is
$$\ce{Au} > \ce{Cu} > \ce{Ag}.$$
What could be a ...
- 39
2
votes
1
answer
56
views
Find the Ionisation Potential and Electron affinity of X
$N_0/2$ atoms of $X_{(g)}$ are converted into $\ce{X^+_{(g)}}$ by energy $E_1$. $N_0/2$ atoms of $X_{(g)}$ are converted into $\ce{X^-_{(g)}}$ by energy $E_2$.
Hence ionisation potential and electron ...
1
vote
1
answer
595
views
Why do PES graphs list 4s after 3d? [duplicate]
Coming straight off of some electron configuration worksheets, our teacher started to teach us how to read photoelectron spectroscopy (PES) graphs and I'm having a bit of trouble with the two.
During ...
- 113
1
vote
1
answer
4k
views
Why is the first ionization enthalpy of molecular O2 less than atomic O?
A cousin of mine asked for my help to answer one of his homework questions. It stated-
Explain why- The first ionization energy of molecular oxygen $\ce{O2}$ ($\pu{1175 kJ mol-1}$), is lesser than ...
- 1,111
-1
votes
1
answer
140
views
More Anti-bonding or less bonding electrons?
Is a molecule more stable with less bonding electrons or more anti-bonding electrons? This question arose when I was asked the stability comparison between $\ce{N2^+}$ and $\ce{N2^-}$.
- 423
-3
votes
1
answer
287
views
When is the process exothermic and when is it endothermic? [closed]
When electrons are being added/removed from atoms or ions how can I tell if the process is exothermic or endothermic? For example in the question below, how could I tell for sure which of the ...
- 25
2
votes
2
answers
567
views
What exactly is lattice energy?
I was going through my chemistry textbook (Chemistry, 10th Ed. by Raymond Chang) when I encountered this explanation of lattice energy.
9.3 Lattice Energy of Ionic Compounds
We can predict which ...
- 131
0
votes
2
answers
1k
views
Why is ionization always an endothermic process?
My textbook says removing an electron always requires an input of heat. That makes sense because of coulombic force between electron and nucleus. But it also says that the process is endothermic ...
- 1,734
1
vote
0
answers
319
views
Do isotopes have the same ionization energy? [duplicate]
When learning about isotopes and IE in High School this question have come to my mind recently. I have asked the teacher, she told me that she read articles about it however could not come to a ...
- 11
1
vote
1
answer
1k
views
Why is ionization energy of indium less than gallium?
In group 13 we observe an irregular trend in ionization energy: B > Tl > Ga > Al > In.
Gallium has a filled 3d subshell, but indium has a filled 4d and 3d subshell. Thus it should have more poor ...
- 11
-1
votes
1
answer
95
views
Ionization and bond energy of isotope [closed]
Is there a database with the direct values, or the ingredients to calculate them, for ionization and bond energies of isotopes (i.e. $^{17}O_2$). If I understand it right, ionization energy can be ...
- 1
-1
votes
1
answer
83
views
Auto-ionization equilibrium of water shifted with acid-base addition? [closed]
Adding acids or bases to water, so that either pH or pOH decreases independently of the other, will that affect the auto-ionization of water? For example, pure water + auto-ionized state, with some ...
- 1
1
vote
1
answer
132
views
Values for heat of reaction example
I am currently studying the textbook Mass Spectrometry, third edition, by Jürgen H. Gross. Chapter 2.4.3 Bond Dissociation Energies and Heats of Formation says the following:
Energetics of $\ce{H}^\...
- 1,053
0
votes
1
answer
658
views
Why is the first energy of ionization of oxygen lesser than that of nitrogen? [duplicate]
The following question arises from a question I found in my book.
Experimentally it has been determined that the value of the first
energy of ionization of oxygen is lesser than the first energy ...
4
votes
2
answers
3k
views
Why Zn has highest ionisation enthalpy in 3d series?
Zn which has the highest ionisation enthalpy in 3d series.The reason given in my textbook is:
The value of zinc is higher because it represent ionisation from 4s level.
This is not correct because ...
- 430
6
votes
2
answers
2k
views
Reorganization during ionisation for d block elements
This is a quote from my textbook:
The irregular trend in the first ionisation enthalpy of 3d lmetals,can be accounted for by considering that the removal of one electron alters the relative ...
- 430
0
votes
2
answers
2k
views
Why does hydrogen have a lower ionization energy than fluorine?
I found here that the ionization energy of hydrogen is $\pu{1312kJ/mol}$ and for fluorine, it is $\pu{1681kJ/mol}$. Now clearly, from the data, we can see that hydrogen has a lower ionization energy ...
user88339
7
votes
1
answer
376
views
Heats of formation of neutral molecules and homolytic vs heterolytic bond dissociation in mass spectrometry
I am currently studying the textbook Mass Spectrometry, third edition, by Jürgen H. Gross. Chapter 2.4.3 Bond Dissociation Energies and Heats of Formation says the following:
Great efforts have been ...
- 1,053
0
votes
1
answer
3k
views
The second Ionisation energy of the Zn, Cd, and Hg follows the order?
It is observed that the order of second ionisation energy of these three elements is $\ce{Zn > Cd < Hg}$.
Why is there an anomaly in the observation?
- 315
3
votes
1
answer
1k
views
How to calculate the energy to dissociate a bond into neutral atoms?
I am self studying chemistry through MiT ocw 5.111 . On practice exam 2 problem 2 there is a question which states the following
...
- 133
1
vote
0
answers
653
views
Why is there a big jump in first ionisation energy between sodium and potassium?
I know the trend in group 1 is that ionisation energy decreases down the group due to an increase in atomic radius and more energy levels are added so more shielding, but I'm not sure why there's such ...
- 19