Questions tagged [rare-earth-elements]

According to the IUPAC, the rare earth elements are a group that comprises the fifteen lanthanoides (La to Lu), Y and Sc. These elements are commonly grouped together due to the similarity in their chemical properties.

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Why is there anomalous trend in third ionization energy for Pr-Pm and Dy-Er?

It is not hard to observe the anomalously flat regions at Pr-Pm and Dy-Er in the trend of IE3 of lanthanides:, each described as the "first quarter" and "third quarter". Why is ...
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What is the purpose of the reflux ratio for solvent extraction?

Not distillation If I understand it correctly, in my example, one has two components, A and B, starting at the "feed" in the aqueous phase. They get both extracted in the mixer settler, but ...
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The separation of lanthanum oxide and chromium oxide

I have encountered a problem. How can I separate the alloy of lanthanum oxide and chromium oxide? I attempted to dissolve them in concentrated sulfuric acid with heating, but it didn't work. If I had ...
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f-f transitions and their cause

I was looking at this question: How can f-f transitions happen? And got some answers that answered some of the questions I had, but not all. I am still trying to conceptually grasp why f-f transitions ...
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What do we use Rare Earth Elements/ lanthanides for in geochemistry? [closed]

What kind of things are lanthanides used for in geochemical studies in terms of high temperature igneous systems and dating rocks from the earth, moon, and solar system?
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Measuring Rare Earth Element Concentration in a Solution

I am interested in repeating the experiment as detailed in this paper: Study on Rare Earth Elements Leaching from Magnetic Coal Fly Ash by Citric Acid In the paper, coal fly ash is leached by citric ...
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What are observationally stable elements?

According to Wikipedia, a lot of the elements that have higher atomic numbers than dysprosium have isotopes that say "Observationally stable" instead of stable, for example in Isotopes of ...
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Why do the lanthanides usually use the +3 oxidation state?

This might seem like a silly question, but why do all of the lanthanides use the +3 oxidation state? I know that some of them can use the +2 (europium, ytterbium) and the +4 (terbium, cerium, ...
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How many elements have been identified for which there are no known spectral lines?

Background: @ProfRob's answer to If there were undiscovered elements (119 on) in a star's spectral lines, could we tell? in Physics SE begins: I think that would be very difficult indeed. ...
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In Lanthanides, Why is electron removed from 4f before 5p? [duplicate]

I've been taught that electrons are removed first from valence shell electrons with highest energy. But In Lanthanides, for example taking configuration- [Xe]4f⁴6s², If we go to +3 Oxidation State, ...
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Why are the rare Earth elements divided into light and heavy categories?

Rare Earth's up to z=62 (Samarium) are often called 'light' rare Earths, while z=63 (Europium) and beyond are sometimes referred to as 'heavy' ones. Why such distinction? I didn't have come across (or ...
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Why can’t lanthanum through lutetium and actinium through lawrencium all be in group 3?

In 2015, IUPAC established a task force to “deliver a recommendation in favor of the composition of group 3 of the periodic table.” Not much about their decision-making process has been made known to ...
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Why do the lanthanides and actinides have a 5d and 6d orbital, respectively? [duplicate]

I was taught in school that the rare earth metals were the $\mathrm{f}$-orbital group. Additionally, the Aufbau principle states that the order of orbitals based on energy levels is $\mathrm{6s4f5d}$ ...
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To what degree can the Rare Earth Elements be interchanged in its workaday applications?

In their humdrum pedestrian "high-tech applications due to their unique magnetic properties", how interchangeable are the Rare-Earth Elements (REEs) if, e.g., the US lacks one of them? RRautamaa ...
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Magnetic moment of trivalent lanthanide cations

The effective magnetic moment $\mu_{\mathrm{eff}}$ of tripositive rare earth elements, is calculated by $$\mu_{\mathrm{eff}}=g_J\sqrt{J(J+1)}\mu_\mathrm{B}$$ Why can't we use normal formula as $\sqrt{...
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Separating lanthanides using ion-exchange method

Following statements are on Separation of rare earth metals (lanthanides) via in-exchange method The tripositive ions are strongly sorbed by cation exchange resin: $\ce{La^{3+}}$, the largest is ...
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How can ionic bonding in lanthanides occur without valence orbitals available for overlap?

I've recently been taught that the 4f orbitals in lanthanides are "core-like", supposedly meaning they have radius smaller than the 4d orbitals, therefore they are not available on the outside of the ...
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Nomenclature - Lanthanoids vs Lanthanides (and Actinides vs Actinoids)

Apologies if this seems like a silly question. Rare earth elements (the 4d series) are called by the names Lanthanides or Lanthanoids interchangeably. The same applies for the 5d series, which are ...
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Exceptional electromagnetic properties of lanthanide series elements

Why do so many lanthanide series elements have exceptional electromagnetic properties? They can form strong magnets and are also used in superconducting applications. The number of elements in the ...
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Two different electronic configurations for cerium

Depending on the textbook there are two different electronic configurations stated for cerium. On the one hand $$[\ce{Xe}]\mathrm{4f^15d^16s^2}\quad$$ and on the other hand $$[\ce{Xe}]\mathrm{4f^...
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Cerium electronic configuration change from 0 to +2 oxidation state

Cerium in $0$ oxidation state has electronic configuration $$[\ce{Xe}]\mathrm{(4f)^1(5d)^1(6s)^2}$$ But when it gets oxidised to $+2$ state, it becomes $$[\ce{Xe}]\mathrm{(4f)^2(5d)^0(6s)^0}$$ ...
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Cerium (CeO) behavior in Glass Polishing?

I am basically working in semiconductor industry and I specifically taking care of CMP (Chemical Mechanical Polishing). We did polish glass (borosilicate type of glass) and we are using slurry (which ...
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Can't nobelium form compounds like other lanthanides/actinides do?

Over the past week I've been browsing through WebElements just to find out some interesting facts/properties about certain elements in the Periodic Table. I've just come across the uncommon element ...
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Europium stability in +2 and +3 state

I would like to ask a question about europium's stability in the $+2$ and $+3$ oxidation state. The electronic configuration of europium in its neutral state is $\ce{[Xe] (4f)^7 (6s)^2}$. Now, when ...
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Why is gadolinium specifically used in MRI contrast agents?

Gadolinium(III) chelate complexes are routinely used as contrast agents in magnetic resonance imaging (MRI);1 the usual explanation is that paramagnetic species contain unpaired electrons, which cause ...
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Going from La to Ce, why is the extra electron added into the 4f orbital?

So, I am studying electronic configuration but the elements of the series of the lanthanides confused me. The electronic configuration of $\ce{La}$ is $\mathrm{6s^2\,5d^1}$ and that of cerium is $\...
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Why are actinides not commonly included in rare earth metals?

According to the German Wikipedia, the rare earth metals include all elements of the third side group except actinium, and all lanthanides. Zu den Metallen der Seltenen Erden gehören die chemischen ...
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What causes the "Gd break" in the trend of lanthanide-EDTA formation constants?

Smith and Martell obtained a series of data for the binding of trivalent lanthanide ions, $\ce{Ln^3+}$, with various carboxylic acid ligands (amongst them the well-known EDTA).1 A graph of the ...
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Causes for the irregular electron configuration of the lanthanides

I know what the electron configurations of the lanthanides are, but I was asking myself, why they are so irregular. The configutation of Lanthanum is $\mathrm{5d^1\ 6s^2}$, but according to the ...
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Which of these are more reactive: the lanthanides or aluminium? [closed]

I am not sure whether to consider the standard reduction potential or ionisation enthalpy. Which of these are more reactive: the lanthanides or aluminium?
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Absorption and ionization of rare earth ions

I'm studying silicate photosensitive glasses that contain $\ce{Ce}$ ions, and such glasses have an absorption band at 305 nm due to $\ce{Ce^3+}$. After that, the $\ce{Ce^3+}$ ion becomes $\ce{Ce^4+}$, ...
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Why are the densities of europium and ytterbium anomalously low?

Why do europium and ytterbium have lower densities than expected in comparison to other lanthanides? I know it has something to do with the fact that they have half-full and full 4f subshells in the +...
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For alkali and lanthanide metals, is there a better liquid barrier to oxidation than mineral oil?

Most often mineral oil is used to store, protect reactive metals from oxidation. By far the best choice is to hermetically seal the metal in pure argon or some other inert gas, since, although mineral ...
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Lanthanides react with mineral oil?

I have an element collection and noticed that the lanthanide (rare earth) element samples seem to be reacting with the mineral oil I've used to help prevent oxidation. When I originally placed the ...
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Deviation of Ytterbium from general trend

What is the reason for deviation of ytterbium from the general trend of lanthanides in terms of hardness, melting point, density etc.?
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Exceptions to the Madelung rule for electronic configurations

The electronic configuration of platinum is $$\mathrm{[Xe] 4f^{14} 5d^9 6s^1}$$ and not $\mathrm{[Xe] 4f^{14} 5d^{10} 6s^0}$ or $\mathrm{[Xe] 4f^{14} 5d^8 6s^2}$. I see this question has already ...
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electronic configuration of lanthinide series [duplicate]

Why does the 57th electron enter the $5d$ subshell in lanthanum, shouldn't it should enter the $4f$ subshell according to the Aufbau rule? Also in thorium, the 89th and 90th electrons enter the $6d$ ...
Mayank Trikha's user avatar
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Why is europium used in Euro bank notes?

Europium is apparently used as an anti-counterfeiting measure in Euro bank notes because of its fluorescence under UV light. Is there any reason why it is specifically $\ce{Eu}$ and not any of the ...
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Separating metals out of a magnet

I have acquired the crushed magnet out of a motor I was given. If I'm correct that the magnet is $\ce{NdFeB}$ magnet, how could I separate out all the metals into a pure or oxide form? And for hard ...
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How do I make a dysprosium chloride solution from dysprosium oxide?

I know that dysprosium oxide is insoluble in water. I was told that I need to add concentrated $\ce{HCl}$ to the compound and then evaporate the $\ce{HCl}$ off. From looking at the reaction equation, ...
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Why is the +3 oxidation state of Cerium more stable than +4?

For the 4f inner transition metals, +3 is the most common oxidation state (OS). Why is the +3 OS of cerium considered more stable than +4, at which it attains noble gas configuration?
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Relativistic effects and lanthanide contraction

So I understand than the lanthanide contraction is due to poor shielding of the 4f electrons which decreases the radius. However, if Im not mistaken the relativistic effects lead to a contraction of ...
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Yttrium -- rare earth or transition metal?

The element yttrium is called a rare earth element, yet periodic tables label it as a transition metal. Why is that? Thanks
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Why are the rare earths erbium (Er), terbium (Tb), yttrium (Y) and ytterbium (Yb) named like that?

I know the history of the discovery of the rare earth elements, that they were discovered near the village Ytterby in Sweden in the 19th century. Four elements are directly named after that village: ...
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