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Why doesn't ionization energy decrease from O to F or F to Ne?

It's a good question, and I agree that it can be quite confusing, but Chemguide is (at least partly*) correct about this. I'd phrase it this way, which I hope is clearer. First, think about what would ...
orthocresol's user avatar
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12 votes
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Ionization energy of beryllium

In terms of Bohr model ionization potential $E_\mathrm{i}$ is the work $A_\mathrm{i}$ on eliminating an electron in vacuum from its current non-excited orbital level to infinity: $$E_\mathrm{i} = \...
andselisk's user avatar
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10 votes

Is the first ionization energy in oxygen slightly more than nitrogen?

Oxygen has a lower first ionization energy as the electron that is removed is coming from a paired orbital. Electrons within the same orbital experience maximum repulsion as the distribution of ...
Withnail's user avatar
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10 votes
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Why does magnesium have a greater ionization energy than lithium?

The book has omited the other factors. The short answer is: In spite of the bigger atomic radius, the valence electrons of magnesium are attracted by the greater net electrostatic force compared to ...
Poutnik's user avatar
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9 votes
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Why lithium gives flame coloration?

I would love to find numbers, but alas, I have failed. If anyone can point me towards energy differences between the orbitals I am lacking, please feel free! There is no a priori physical reason why ...
Jan's user avatar
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9 votes
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Can visible light or infrared radiation excite electrons?

Different regions of the electromagnetic spectrum correspond to different atomic and molecular processes, each with one or more associated spectroscopies. Here is a general summary, with decreasing ...
pentavalentcarbon's user avatar
8 votes

Why does the ionization energy decrease anytime the atom size increases?

The ionization energy is the lowest amount of energy required to remove one electron(the most loosely attached electron) from each atom in one mole of an element in gaseous state to form gaseous (...
Estine Winchester's user avatar
8 votes
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Successive ionization energies (work functions?) for metals

In an infinite metal solid, there are an infinite number of electrons, so each one removed will be at the exactly identical work function with no change in energy. Intuitively, this may seem a bit ...
Geoff Hutchison's user avatar
7 votes

What happens to the first ionization potential when a hydrogen-like atom captures a particle?

When we solve the Schrodinger equation for the hydrogen atom we general make the simplifying assumption that the proton stays fixed and the electron moves in the potential of the fixed positive charge....
John Rennie's user avatar
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7 votes

In an emission spectrum, the limit of convergence at higher frequency corresponds to the first ionization energy

This is an excellent question! Just to elaborate upon what @porphyrn and @M. Farooq have said, imagine that the universe is entirely empty except for one sodium atom and one photon (particle of light) ...
Ed V's user avatar
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7 votes
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Reason for usage of Metal chlorides and Platinum or Nichrome wires in flame test

Metal chlorides are usually much easier volatilized than oxides or sulfates. They melt or sublime at temperatures much lower than 800°C. So they are volatilized in any flame like Bunsen burners. ...
Maurice's user avatar
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6 votes
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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?

As mentioned by Zhe, we have to look at the entire process by which an ionic compound is formed, not just the energy for a single part. For example, consider the formation reaction of $\ce{MgO}$ $$\ce{...
Tyberius's user avatar
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What is the element with the greatest first ionization energy?

Your book must be wrong. NIST gives these values (in eV) as 11.260300 for C and 12.96763 for Cl. Even not reaching that website, I would say that a halogen would have a higher ionization potential ...
MEL Science's user avatar
6 votes
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Ionization energy of C2-, C2, and C2+

Bond order has to do nothing with ionization energy, it is the bond dissociation energy which has to be dealt with bond order. For minimum ionization energy, the electron has to be lost from the ...
Soumik Das's user avatar
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6 votes
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Heat of formation of aqueous H⁺

Where am I going wrong here? Your chemical reaction is not balanced. You wrote $$\ce{1/2 H2(g) -> H(g) -> H+(g) -> H+(aq)}$$ but it should be $$\ce{1/2 H2(g) -> H(g) -> H+(g) + e- (...
Karsten's user avatar
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6 votes
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Why is the 2nd ionization energy of chloride similar to that of sulfur?

The second ionization of chlorine leaves $[\text{Ne}]3s^23p^3$ where the $3p$ subshell is half-filled with one electron per orbital and gives a favorable exchange energy. With sulfur this relatively ...
Oscar Lanzi's user avatar
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Why is a sodium chloride molecule stable?

What you have calculated is the energy required to make two separated ions out of two separated $\ce{Na}$ ad $\ce{Cl}$ atoms. When they are separated, these ions do not make a molecule or a crystal of ...
Maurice's user avatar
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5 votes

If fluorine has a lower electron affinity than chlorine, why does it have a higher ionization energy?

To quote chemguide: The first ionisation energy is the energy required to remove the most loosely held electron from one mole of gaseous atoms to produce 1 mole of gaseous ions each with a charge ...
DHMO's user avatar
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5 votes

Why do cations have higher ionization energies than their corresponding neutral atoms?

Consider a simple thought experiment. Your ionisation process is essentially removing a (negatively charged) electron from a remainderatom. $$\ce{Atom^n+ -> Remainderatom^{(n+1)+} + e-}$$ ...
Jan's user avatar
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5 votes

Why is the first ionisation energy of a sodium cation bigger than that of a neon atom?

A sodium cation $\ce{Na+}$ and a neutral neon atom $\ce{Ne}$ are isoelectronic species; meaning they have the same number of electrons and also the same electronic configurations. Yet, the two have ...
Jan's user avatar
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5 votes

Why is electron gain generally exothermic?

Looking at the comment thread above, I believe a bit more elaboration can help, so here it is Why is electron gain generally exothermic? Think of a unit positive sphere and a unit negative sphere. ...
Gaurang Tandon's user avatar
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Why is the first ionization enthalpy of zinc higher than expected?

It is because the shell is complete. Zinc's electronic configuration is $\rm [Ar] 3d^{10} 4s^2$, which is a complete configuration for a transition metal. The next element in the same period is $\ce{...
user30149's user avatar
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5 votes

Why lithium gives flame coloration?

Expanding a bit on the last paragraph of Jan's answer: The best explanation I have for the colourlessness of magnesium and beryllium is that their excitations are too close to ultraviolet to be ...
hBy2Py's user avatar
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5 votes

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

Not only can $\ce{Ne^{8+}}$ exist, it probably does in the Sun's corona. And we may even have $\ce{Ne^{9+}}$ there. Coronium During the total solar eclipse of 1769, two scientists independently ...
Oscar Lanzi's user avatar
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5 votes

Why is the photon energy of lithium flame coloring lower than that of cesium?

To estimate the approximate wavelength of electronic transitions is alkaline metals, the Rydberg formula $(1)$ may be used. Strictly speaking, it is only valid for hydrogen and hydrogen-like atoms ($\...
Jan's user avatar
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5 votes

is Li ion less stable than Li atom?

What do you mean by "stable"? In a vacuum, $\ce{Li+}$ is quite stable. In water, Li ionizes readily to $\ce{Li+}$, with $\ce{OH-}$ accepting that electron. Of course, in vacuo, if an $\ce{Li+}$ ion ...
DrMoishe Pippik's user avatar
5 votes

Electron Ionization and the Franck-Condon Diagram: vibrationally excited and vibrationally ground states

The reasons for the change in internuclear separation and the imporance of the Franck-Condon factors, as has been clearly pointed out in answers and comments. The FC factors determine the strengths ...
porphyrin's user avatar
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5 votes
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How to calculate the energy to dissociate a bond into neutral atoms?

Your $\pu{640 kJ mol^-1}$ value is correct, so the next step is to neutralize the ions. First add an electron to a potassium ion to get a potassium atom. This releases $\pu{418 kJ mol^-1}$ because it ...
Ed V's user avatar
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Are there any monocations with negative electron affinities known?

A monocation with an endothermic (negative) electron affinity is the same as a neutral species with an exothermic (negative) ionization energy. Reframing it this way may turn up more information. The ...
Nicolau Saker Neto's user avatar
4 votes
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Why is the photon energy of lithium flame coloring lower than that of cesium?

The colours you get in flame tests / burning metals, comes from the electrons in one shell being 'knocked' (by the heat), into a higher shell; then shortly after the electron 'drops' back (in one or ...
DarcyThomas's user avatar

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