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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].

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Can you in reality give neon a charge of +8?

First off, I am currently confused about why neon can even be ionized at all. But since it can be ionized, this is the energy required to give a mole of neon a charge of +8: ...
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Why is electron gain generally exothermic?

I understand that we need to supply energy to counter the nuclear attraction when we remove electrons, and that is the reason why ionization energy is endothermic. However, why does an atom release ...
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Ionization energy of beryllium

Suppose I have $\ce{Be^3+}$. What would be its 4th ionization energy? By trying to solve the issue I saw that its a "hydrogen-like" atom – means that beryllium left with only $1$ electron in his ...
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is it possible to break the bonds of diatomic elements such as fluorine or iodine and create positive and negative ions by electron bombardment?

If I had a container in vacuum filled with $\ce{I2}$ gas and then I bombarded it with high speed electrons using an electron gun, would be able to get both $\ce{I+}$ and $\ce{I-}$ ions or would I ...
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In an emission spectrum, the limit of convergence at higher frequency corresponds to the first ionization energy

This is one of the syllabus points in the IB syllabus 12.1. We are advised to use the formula for the energy to remove one electron: $$E = hν$$ which apparently is the same as $$E_2 - E_1$$ where $...
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What is the range of photon energies can be effectively used to split a diatomic molecule like hydrogen?

I saw photo-ignition of hydrogen-chlorine mixture using UV light on YouTube. Chlorine molecule bond dissociation energy is $\pu{2.51 eV}$ (bluish colour). Bromine molecule bond dissociation energy is ...
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Why lithium gives flame coloration?

Theoretically speaking, beryllium and magnesium does not give flame test because their atoms are comparatively smaller and the valance electrons are strongly attached to the nucleus. Therefore their ...
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Why is the photon energy of lithium flame coloring lower than that of cesium?

Why does $\ce{Li}$ give a red flame color which has lower photon energy compared to $\ce{Cs}$ which gives a violet flame color according to $E=h\nu$? This is my attempt: Since lithium has smaller ...
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Second ionization potential of Gadolinium

I notice that Gd has a second ionization potential which is significantly higher than would be expected from the general trend in the lanthanides (see this paper p. 945 for a graph). What is the ...
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Why does aluminum have a lower first ionization energy than magnesium?

I used to use the explanation that $s$ orbitals penetrate better than $p$ orbitals, however, could the explanation be that $3s$ is shielding the $3p$ in aluminum?
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Why is Ionization Energy definition restricted to gaseous atoms?

Here's the definition of ionization energy that I am learning at this level: energy required to remove 1 mole of electrons from 1 mole of gaseous atoms to form 1 mole of uni positively charged ...
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Why is the ionization enthalpy of francium greater than that of cesium?

Why is the ionization enthalpy of francium greater than that of cesium, even though it has a larger size? I found no Google result regarding this.
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Ground state oxidation potential and Ionization potential from density functional theory (DFT)

Can someone please tell me how to calculate the ground state oxidation potential (GSOP)? I understand that according to Koopmans' theorem, the negative of HOMO can be considered as the GSOP. Is there ...
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How can I relate the reactivity series to electronegativity and ionization energy?

I am trying to figure out how the reactivity series comes about. My understanding is that elements with a higher electronegativity will be more reactive than elements with a lower electronegativity, ...
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Why does iron have an abnormally high ionization energy?

Along a period the ionization energy should increase because the atomic number is increasing, but there is negligible increase in shielding. However, $\mathrm{IE}_\ce{Mn} < \mathrm{IE}_\ce{Fe} > ...
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What happens to the first ionization potential when a hydrogen-like atom captures a particle?

This is a textbook problem from Resonance DLPD Physical Chemistry, Page #83: The mass of a proton is $1836$ times the mass of an electron. If a subatomic particle of mass $207$ times the mass of an ...
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The ionization energy of H₂⁺ molecule ion

I am trying to compute the ionization energy of $\ce{H2+}$ molecule ion from the electronic energy spectrum. The question is whether one should use the purely electronic Hamiltonian or the Hamiltonian ...
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Why does the ionization energy decrease anytime the atom size increases?

I would like to have a better understanding of the relationship that exists between the Ionization Energy commonly known as IE and the size of an atom. I think that the Ionization Energy can be ...
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Why is the common magnesium ion Mg(II) and not Mg(I) when the second ionization energy is higher than the first ionization energy?

The first ionization energy for magnesium is given as $\pu{737.7 kJ/mol}$, and the second ionization energy is $\pu{1450.7 kJ/mol}$. Given this information, doesn't it take $\pu{737.7 kJ/mol}$ to ...
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Ionization energy of C2-, C2, and C2+

My textbook says that $\ce{C_2}^-$ has a lower ionization energy than both $\ce{C_2}$ and $\ce{C_2}^+$. I calculated that the bond orders of $\ce{C_2}^+$, $\ce{C_2}$, and $\ce{C_2}^-$ are 1.5, 2, and ...
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Estimation of pressure and kinetic energy density of stellar interior using kinetic theory of gases

In Physical Chemistry we are working a problem that is confusing. We started by calculating the pressure half way to the centre of the sun assuming that the interior consisted of ionized hydrogen ...
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Anomalous trends in ionization energy

I want to address two exceptions in the trend of ionization energy across the period, that are causing me problems: Taking the second period as an example : The two exceptions from the general trend ...
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How adding one more electron increases the ionization energy?

Elements of group 6A, compared to 5A, require less ionization energy due to the paired electrons of 6A. But a question arises: why does group 7A, compared to group 6A, require more ionization energy ...
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Volume of orbitals

As I was learning about atomic structure, the lecturer made a seemingly dubious claim: The volume of a p orbital is one-third that of the s orbital. Thus, inter-electronic repulsions are ...
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Can the first ionization energy for a specific element be calculated?

I'm taking a first-year Inorganic Chemistry course in college, and stumbled upon this problem: For $\ce{Mn}$ and $\ce{P}$, calculate the first ionization energy and explain the difference between ...
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Why isn't ionization energy called cationization energy? [closed]

I'm learning chemistry and ionization energy is "[...] the amount of energy required to remove the most loosely bound electron, the valence electron, of an isolated gaseous atom to form a cation." It ...
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Stability of unsaturated syn/anti 3-ladderane

In an oral exam for physical organic chemistry, one student was asked to explain the differences in the ionization potential ($IP$) of syn and anti tricyclo[$4.2.0.0^{2,5}$]octa-3,7-diene (unsaturated ...
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Why don't halogens form cations like H+?

The first ionization energy of hydrogen is $1312\;\mathrm{kJ\cdot mol}^{-1}$, which is larger than that of halogens such as chlorine, bromine, and iodine. Given that observation, why don't halogens ...
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Signs of Exchange and Correlation Potentials

The exchange and correlation potentials refer to those defined in density functional theory. (See also http://en.wikipedia.org/wiki/Local-density_approximation) Define the exchange potential as $V_{x}...
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Is the first ionization energy in oxygen slightly more than nitrogen?

Why is the first ionization energy in oxygen slightly more than nitrogen? In nitrogen: $\ce{[He] 2s^2 2p^3}$ In oxygen: $\ce{[He] 2s^2 2p^4}$ This tells me that it should be easier to remove an ...
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Why is the 2nd ionization energy of chloride similar to that of sulfur?

The first ionization energy of chloride is significantly greater than that of sulfur. I suggest that this is very expected as the effective nuclear charge of chloride is higher and additionally, ...
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If fluorine has a lower electron affinity than chlorine, why does it have a higher ionization energy?

I have read that fluorine has a lower electron affinity than chlorine despite its lower atomic radius because its electron cloud is extremely dense. If this is the case, shouldn't the ionization ...
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DFT Calculations, Atomic Ionization Potentials — Which Exchange-Correlation Functional to Use, to Preserve Koopmans Theorem?

I have a program which can perform density-functional calculations for atoms, given a density functional. Of course the simplest form of exchange potential to use is one relevant for a uniform ...
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1answer
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Does caesium or francium have a lower ionization energy?

$\ce{Cs}$ and $\ce{Fr}$ are in the same group of lowest first ionization energy, but which element has the lowest ionization energy, and why?
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How to tell which compound has the biggest ionization energy?

I am preparing for my final exam, and I am very confused about ionization energy. An example question would be: Between the species $\ce{Ne, Na+, Mg^2+, Ar, K+, $\&$~Ca^2+}$, which one has the ...
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Does ionization energy have anything to do with how reactive an element is?

According to my textbook, fluorine has a pretty high (compared to elements like sodium) first ionization energy. But why does it have such a high requirement to ionize? After all, it actively seeks ...
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Energy comparison between an atom and its ion

Is it possible to compare energy(enthalpy or similar) between an atom and its ion, possibly in the same state(gas)? For example, $\ce{O}$ and $\ce{O^+}$(intentionally cation), $\ce{Na}$ and $\ce{Na^+}...
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Successive ionization energies (work functions?) for metals

Are there tables for successive ionization energies for metals (like for gases)? All I can find are work functions to remove one electron from the surface of a metal into vacuum (and to keep it there)....
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Why is the ionization energy for Hydrogen non-zero?

There are no other electrons to collide, repel and kick Hydrogen's single electron to a distant nucleus. And that a single electron is tightly attracted to the nucleus by the electrostatic energy ...
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Can visible light or infrared radiation excite electrons?

So the limit of ionizing radiation seems to be UV light. I'm wondering if IR light or Visible light can excite the electrons in an atom. It has to do with the difference in energy level right? So ...
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Why is the first ionization enthalpy of zinc higher than expected?

The following sentence is stated in my current chemistry book: The first ionization enthalpy of zinc is higher because it represents an ionization from the $\rm 4s$ level. Now zinc does have an ...
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1answer
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Relation between ionisation enthalpy and nature of bonds in boron

My notes given by institute states that: Due to small size of boron, the sum of its first three ionization enthalpies is very high. This prevents it to form $+3$ ions and forces it to form only ...
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Compare the ionization energies of C and Cl?

I saw a test question today that basically boiled down to comparing the ionization energies of $\ce{C}$ and $\ce{Cl}$. I know that in the periodic table, ionization energy generally increases as we ...
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1answer
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Ionisation Energy vs First Ionisation Energy [closed]

It was stated in a textbook that the first ionisation energy is the minimum energy needed to remove one mole of electrons from one mole of gaseous atoms in their ground state Is there a difference ...
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1answer
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Why does F have a higher ionization energy than O?

The book I'm working from says F has a higher ionization energy than O because the nucleus has more protons so there is a higher attraction on the electrons. Isn't that balanced out by the higher ...
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1answer
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Removing ozone from a gas flow

I have a potential problem in that I need to reliably remove ozone from a stream of ionized gases, mostly air. The flow rate is quite low, less than 400 sccm. I was thinking of something catalytic, ...
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Reason for the differences in third ionisation energy between elements (magnesium and fluorine)

The question is "Why is the third ionisation energy of magnesium higher than that of fluorine?" Although I understand that differences in ionisation energy have several factors governing it, e.g. the ...
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Determine stable oxidation state from Ionization energy

Question: Given the first, second and third ionization energies of an element (7 eV, 12.5 eV and 42.5 eV respectively), how would one find the most stable oxidation state (or charge on the resultant ...
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1answer
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Periodic trends: why is effect of protons greater than electrons?

Why is it that adding protons has a greater effect than electron-electron repulsion on periodic trends like atomic radius and ionization energy (assuming # of shells constant)? It seems that if ...
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1answer
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Order of second ionization energy for cations

Why is the correct order of second ionisation potential of $\ce{Li , Be , B , C }$ such as: $\ce{Be} <\ce C <\ce B <\ce{Li} $? I understand that $\ce{Li+}$ has a stable inert gas electronic ...