In atomic physics and quantum chemistry, the electron configuration is the distribution of electrons of an atom or molecule (or other physical structure) in atomic or molecular orbitals.

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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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What is the electronic configuration of Fe(II) ion?

The electronic configuration of Fe is 1s2 2s2 2p6 3s2 3p6 4s2 3d6. So after removing two electrons the configuration becomes: 1s2 2s2 2p6 3s2 3p6 3d6 But why cant the electrons rearrange themselves ...
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A unique demo for singlet oxygen?

I have long known that mixing bleach and peroxide produces oxygen gas: $$\ce{NaOCl + H2O2 -> O2 + H2O + NaCl}$$ However I only recently learned that the specific form of oxygen produced by the ...
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2answers
41 views

abbreviations in electronic configurations

I am teaching my students how to write the electronic configuration of the elements of the periodic table. Thus, following the rules on how to fill the orbitals, the electronic configuration of iron ...
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21 views

degeneracy and Mendeleev table [closed]

A very basic question. When we construct Mendeleev table we can think of adding one electron at a time, filling one by one the electronic states, that are numbered by well known quantum numbers (using ...
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92 views

Hybridization of the oxygen in furan?

I fail to understand why the hybridization of oxygen in furan is $\ce{sp^2}$. I think that since there are 2 bond pairs and two lone pairs so it should be $\ce{sp^3}$ hybridized? Is it to do with the ...
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sp² hybridized orbital

I do not understand why and how an atom with $\ce{sp^2}$ hybridization has only one p orbital?? For example in pyridine why is the lone pair of nitrogen not counted as a pi electron.
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31 views

What does this property of transition metals mean? [duplicate]

what does it mean: "Transition metals either have incompletely filled d subshells or readily give rise to cations that have incompletely filled d subshells. I don't understand the portion starting ...
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37 views

Electron Configuration of an element with no. of electrons > 18

Let's say that we have an element, say $\ce{Ca}$. According to law, the last shell should contain only upto 8 e-. Hence, electronic configuration of $\ce{Ca}$ would be 2,8,8,2. But, according to the ...
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54 views

Why does the electron configuration for some elements not follow the diagonal rule?

I'm doing a high-school assignment, and I came across a question that I didn't quite understand. Explain how the electron configurations for the following elements do not follow the diagonal ...
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41 views

Why is it that weak bases usually contain a Nitrogen?

Why do weak bases usually contain a nitrogen, I know there are two electrons on top for a bond of H but why is it mostly nitrogen? I know there are other elemental bases too but why do I keep seeing ...
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47 views

Is it possible to calculate atomic radius with electron configuration?

I need to know whether is it possible to calculate the atomic radius according to the number of electrons and electron configuration. Or is there any way to calculate the atomic radius using common ...
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Why are d-orbitals required/used for hypervalent molecules (where the central atom has expanded its octet) [duplicate]

Period 2 elements like carbon, oxygen and nitrogen cannot expand their octet because they cannot make use of d orbitals in that energy level (they don't exist). However, period 3 elements like sulfur ...
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61 views

Why the second ionization energy of helium is greater than the first? [closed]

maybe because the first electron has a lower energy. Why does this happen?
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65 views

What is the usage of orbitals more complex than f orbitals?

Every high school learner, in each corner of the world, faces the lesson History of Atom during his courses, just as I did. We learned about s,p,d and f orbitals, though there were no signs of ...
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56 views

How to find the possible valence states of elements in the lower end of the d block and the f block?

For silver, why don't the electrons in the 4d orbital move to the 5p orbital? Is it possible for any elements to move their electrons between $n$d and $(n+1)$p orbitals? When the f orbital is ...
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23 views

Why don't electrons pair up in an oxygen radical?

In an oxygen radical (produced by the break down of O3 for instance), there are 2 unpaired electrons in the outermost subshell which make the molecule unstable. Why don't these electrons pair up which ...
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50 views

Some abnormalities in the Periodic Table

I observe some elements like $\ce{Cr}$ and $\ce{Cu}$. Some of them have strange oxidation numbers that don't really fit the purpose of making the element as stable as possible. Just Chromium, for ...
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2answers
47 views

What is a good (small) model system for ligand metal charge transfer practises?

I am looking for an easy to calculate model system in which I could see a ligand metal charge transfer. Basically I am looking for a model complex, that might have the metal/ligand in different ...
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34 views

How can I interpret the colour of flames in terms of spectral series?

I saw different colors of fire burning different metals. But how does this work? The Balmer series requires electrons to drop back down to n = 2. But, not all alkali metals have empty space in their ...
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36 views

Form the oxides of the element Z=39

Its electronic configuration is $4d^15s^2$ so in normal state it has valence=1 and in energetic state, valence=2 (because our teacher said we count only the electrons in the outer shell firstly) and ...
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70 views

What determines how favorable (exothermic) is the electron affinity of a certain element?

(Favorable means how exothermic a reaction is, more favorable= more exothermic) There are some abnormalities in the trends of how favorable the electron affinity is. From Al to Cl, the ...
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1answer
35 views

Electron shell, how do they know it?

I started to learn Chemistry with something like Hidro have 1 electron in the first shell, Oxigen have 2 electron in the first shell and 6 electron in the second shell... But I don't really understand ...
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45 views

Find the valences of Z=26

I've tried this: But its hows that the valence of Fe in normal state is 4, when in the periodic table it isn't. Why does this happen? Can you show me the answer with configuration formula in the ...
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30 views

A way to calculate orbital energy of an electron

Maybe this is just not included in my course, but I still wonder how to calculate the binding energy of an electron .at a certain electron orbital. Intuitively,The ionization energy of an element ...
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1answer
41 views

Which electrons will be taken when oxidations take place and how does the resulting orbital diagram look like?

In detail, what I really mean is which electron in which orbital is being taken when a oxidation happen? Let me give a example: chromate ion(II) Two electrons are taken but from which orbital:
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Properties of f-orbitals

I am not a Chemist, but I took enough undergraduate Chemistry classes to understand the basic properties of s, p and d orbitals and how the behaviour of electrons contributes to different kinds of ...
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59 views

how many electrons are in the second subshell of this element?

first of all sorry if I have some mistakes in my "chemistry words", I'm Iranian and I know the Persian terms but only some of the English ones. So suppose we have an element (x) with the atomic ...
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85 views

Why is there an exponent 4 after the brackets in sp3?

My professor wrote an electron configuration for carbon as: 1s2 (sp3)4 I thought it was just 1s2 sp3 where did the 4 come from?
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How does the radial distribution function of Vanadium differ from that of Calcium and how does this affect the ionic electron configurations?

When Vanadium is ionised it loses the 4s electron first, meaning that it's 3+ ion has a different electron configuration to Calcium despite it being isoelectronic. Can it be explained in terms of ...
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What's the electronic configuration of Nickel and Oxygen in RNiO3 (R=Rare-Earth)?

Nickel's electronic ground state is $\mathrm{3d^8 4s^2}$ (there's a dispute on this, but let's not worry about it for now). Oxygen's is $\mathrm{2s^2 2p^4}$. In a Rare-Earth based Nickelate with ...
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1answer
106 views

Doesn't the fact that the lone pair on the nitrogen in amides occupy a p orbital contradict Hund's rules?

Since the $\ce{sp^2}$ hybridized orbitals are lower in energy than the p orbital shouldn't the $\ce{sp^2}$ orbitals fill first? Why is this not the case - two electrons fill the p orbitals while all ...
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Difference between shells, subshells and orbitals

What are the definitions of these three things and how are they related? I've tried looking online but there is no concrete answer online for this question.
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Electron interference

Assuming that electrons behave as both waves and particles, and that waves(like in double slit experiment) can interfere with themselves: Do electrons actually move in any direction, or do they just ...
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Can the electron configuration of Te be written that way?

Normally, the electron configuration of Te is known as: $$\begin{aligned} {[Kr]} 5s^2 \ce{4d^10} 5p^4 \end{aligned}$$ Then, one day I was asked in a exam if this can be written also as: ...
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Is my analysis of quantum numbers describing the ground state of At correct?

Which series of quantum numbers describes the highest (energy) occupied orbital in a ground state of At atom? a) n = 6, l = 0 b) n = 6, l = 2 c) n = 5, l = 2 d) n = 4, l = 3 e) n = 6, l = 1 ...
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836 views

An atom of silicon in its ground state has how many electrons with quantum number l = 1?

I was solving practice problems for electron configuration and periodic table, and I got stuck through a question: An atom of silicon in its ground state has how many electrons with quantum number l ...
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Why does K⁺ have 0 valence electrons?

If we take a K atom and take away an electron why does it now have 0 valence electrons as it states in my General Chemistry textbook? I would think that if we do this, it would have the same exact ...
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57 views

Is there a general method for working out electron configurations?

For up to period 3, elements' electron configurations are relatively easy to work out until the transition metals begin. Then some elements may have $\ce{4s}$ orbitals which are preferred by electrons ...
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Why does gallium nitride allow an AESA radar to be more powerful than a radar with elements made of gallium arsenide?

AESA (Actively Electronically Scanned Array) radars use thousands of individual transmit/receive elements to create a radar. All in service AESAs use gallium arsenide as the material in the t/r ...
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Why do different impurities create different colors in diamonds?

Traces of nitrogen make diamonds yellow while traces of boron make them blue. What accounts for the differences in color for a given element?
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How can I tell what colour an element will be? [duplicate]

Previously in my Chemistry education, it was required of us to memorise the colour changes some elements, especially transition metals, go through. Currently we learning about electron configuration ...
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How much energy does it cost to have electron configurations that are not in accordance with Hund's rules?

What is a ballpark figure for the difference in energy for an atom that follows Hund's rule vs one that has two electrons with opposite spins? I'd be interested to know carbon and nitrogen. Is there ...
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What would the Electronic Configuration of Ru²⁺ be?

I'm doing homework for Inorganic Chemistry, and I am a little confused. The Question is: What is the electronic configuration of $\ce{Ru^{2+}}$? If I were to remove from the highest energy ...
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Why do Group 10 transition metals (and Cu) lose an S electron to fill the D shell? [duplicate]

I don't understand why it varies between Group 10 metals (as with Palladium, Platinum and Darmstadtium) and Copper (Group 11). If each of Palladium, Platinum and Darmstadtium entirely filled the ...
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Determining anomolous electron configuration [duplicate]

There are 21 anomalous elements in the periodic table: $Cr,\, Cu ,\, Nb,\, Mo,\, Ru,\, Rh,\, Pd,\, Ag,\, La,\, Ce,\, Gd,\, Pt,\, Au,\, Ac,\, Th,\, Pa,\, U,\, Np,\, Cm,\, Ds \,and\, Rg.$ I understand ...
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199 views

Photoelectric Effect in Semiconductors

Is the photoelectric effect possible for semiconductors? I imagine that this might be, if possible, a two-photon process: excitation of an electron from a filled to conductance band, and then on to ...
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514 views

What is meant by complete outer shell? Why do the noble gases have zero valency?

Does having 8 or 2 electron in the outmost shell mean its outmost shell is full and its valency is zero? I know that the 3rd and 4th shell can contain 18 and 32 electrons. Then how can Argon's ...
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Electronic configuration of Ace-Ala-Nme

Below is the structure of Ace-Ala-Nme. I have labelled just four of the carbon atoms (1-4 in blue). I need to identify (i) the hybridization state, and (ii) the number of electron withdrawing groups ...
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Explanation for increase in the number of oxidation states for transition elements from Sc to Mn of the 4th period

From Sc, to Mn, the number of oxidation states increases from one (Sc) to seven (Mn). The explanation for this is because the unpaired 3d electrons can be lost along with the 4s electrons during ...