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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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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How to find the formula of an binary oxide based on the ionisation energies? [closed]

I am a little confused about this multiple choice question and what the requirements are to answer it. It is for a year 11 chemistry student that I am helping and I think I am going in a little too ...
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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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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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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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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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Why does the definition of ionisation energy only include gaseous atoms? [duplicate]

I know that in physics there is thermionic emission and the photoelectric effect. These are both method of removing electrons. I think these affects are only for metals due to their de-localized ...
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Determine most electronegative element based on successive ionization energy data

X, Y and Z are three unknown elements whose first 5 ionization energies are given below. Which of the 3 is the most electronegative?$$ \begin{array}{|c|c|c|c|c|c|}\hline &\text{IE}_1&\text{IE}...
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Which of the following atoms has the largest first ionization energy?

Of the following atoms, which has the largest first ionization energy? $\ce{Br}$ $\ce{O}$ $\ce{C}$ $\ce{P}$ $\ce{I}$ I got confused between $\ce{O}$ and $\ce{Br}$. The answer ...
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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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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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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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NaCl dissociation not spontaneous?

It's a well-known fact that the dissociation of $\text{NaCl}$ can be represented by the series of equations $$ \begin{eqnarray*} \text{Na} &\rightarrow& \text{Na}^+ + \text{e}^- \qquad \Delta ...
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Be and B ionization energies

Why does Be have a higher ionization energy than B? I know that it has a filled 2s orbital, but what's the more accurate explanation?
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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 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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Order of second iozination energies of lithium,berillium,neon,carbon and boron?

The correct arrange of them is like this: Be < B < Li ... But why? Li will have the greatest IE2 (second ionization energy) because that will involve removing a core electron, but what I am ...
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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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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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Effect of light on ionic compounds

If I had an ionic molecule which needed $\pu{4 eV}$ to break the ionic bond, a $\pu{7 eV}$ photon is shot at it. If it is absorbed by the molecule and breaks, where does the rest of the energy go?