- Silvery-white metals that tarnish when exposed to air, forming their oxides.
- Relatively soft metals. ...
- Moving from left to right across the period (increasing atomic number), the radius of each lanthanide 3+ ion steadily decreases. ...
- High melting points and boiling points.
- Very reactive.
What are the properties of lanthanides and actinides?
Similarities between Lanthanides and ActinidesBoth have a prominent oxidation state of +3.They are involved in the filling of (n-2) f orbitals.They are highly electropositive and very reactive in nature.With an increase in atomic number, there is a decrease in atomic and ionic size.Both show magnetic properties.
What are 3 characteristics of lanthanides?
The lanthanide metals are soft; their hardness increases across the series. Resistivity of the lanthanide metals is relatively high, ranging from 29 to 134 μOhm·cm. The lanthanides are strongly paramagnetic.
Why do lanthanides have similar properties?
Similarly, the Lanthanides have similarities in their electron configuration, which explains most of the physical similarities. These elements are different from the main group elements in the fact that they have electrons in the f orbital.
What is magnetic properties of lanthanides?
Magnetic properties of lanthanides Because they do not contain unpaired electrons, certain lanthanide ions are diamagnetic, whereas the rest of the elements are paramagnetic at normal temperatures. Below the Curie temperature, which is often quite low, they are ferromagnetic.
Why do lanthanides have 3 oxidation?
The most common and stable oxidation state of Lanthanides is +3.It is attained by removing outermost 2 electrons of 6s electrons and 1 electron from 4f electrons. It is due to high energy difference in 4f and 6s, it is difficult to remove more electrons from 4f sub-shell.
What are the applications of lanthanide?
It is used as a catalyst in the manufacture of petroleum and synthetic products. Thoria and Ceria are used in lamps, magnets, lasers, motion picture projectors, and X-ray intensify screens. Alloys of Lanthanides are used in the instrumental steels, stainless steel, and heat resistance.
Why are lanthanides called lanthanides?
These elements are called lanthanides because the elements in the series are chemically similar to lanthanum.
Are lanthanides reactive?
Like many metals, the lanthanides have a bright silvery appearance. Five of the elements (La, Ce, Pr, Nd, Eu) are very reactive and when exposed to air react with oxygen to form an oxide coating that tarnishes the surface. For this reason these metals are stored under mineral oil.
Why are lanthanides all 3+?
The absence of higher states than 3+ for the Lanthanides is mainly due to the much greater stabilisation of the 4f orbitals compared to 5d and 6s. The order of penetration of the orbitals into the inner electron core is 4f>5d>6s. So the 4f eletrons are the closest to nucleus and attracted by it the most.
Why are lanthanides paramagnetic?
Solution : All lanthanoids except`La^(3+)` and `Lu^(3+)` contain unpaired electrons and hence are paramagnetic.
Why are lanthanides Coloured?
Answer: The colour of lanthanides ions is due to the presence of partly filled & orbitals. As a result, it is possible to absorb certain wavelengths from the visible region of the spectrum. This result in a transition from 4F orbital to another 4F orbital known as the F – F transition.
Who discovered lanthanides?
scientist Carl Gustav MosanderIt was one of the earlier lanthanides to be discovered, by the Swedish scientist Carl Gustav Mosander, working at the famous Karolinska Institute in 1839, though it was 1923 before the pure metal was produced.
Electronic Configuration
Lanthanides of the first f-block have a terminal electronic configuration of [Xe] 4f1-14 5d0-1 6s2. Promethium (Pm), with atomic number 61, is the sole synthetic radioactive element among the fourteen lanthanides. Because the energies of 4f and 5d electrons are so similar, the 5d orbital remains unoccupied and the electrons enter the 4f orbital.
Physical Properties
Because density is the ratio of a substance’s mass to its volume, the density of d-block elements will be greater than that of s-block elements.
Properties of Lanthanide Series
If we include the lanthanides and actinides series in the periodic table, the table will be excessively large. These two series are located at the bottom of the periodic table and are known as the 4f series (Lanthanods series) and the 5f series (Actanoids series). The 4f and 5f series are referred to as inner transition elements.
Lanthanide Contraction
Because of the increasing nuclear charge and electrons entering the inner (n-2) f orbitals, the atomic size or ionic radius of tri positive lanthanide ions decreases steadily from La to Lu. Lanthanide contraction refers to the steady decrease in size with increasing atomic number. Its ramifications are as follows:
Oxidation State
The lanthanide series elements all have an oxidation state of +3. Previously, some metals (samarium, europium, and ytterbium) were thought to have +2 oxidation states. Further study of these metals and their compounds has revealed that all lanthanide metals have a +2 oxidation state in their solution complexes.
Chemical Reactivity
The reactivity of all lanthanides is similar, however it is larger than that of the transition elements. This is owing to the outer 5s, 5p, and 5d orbitals protecting unpaired electrons from the inner 4f-orbital.
Sample Questions
Question 1: What are lanthanide series? The lanthanide series has how many elements?
What are the characteristics of lanthanides?
There are a few characteristics of lanthanides that are certainly worth mentioning. First is their oxidation state. Lanthanides are known to adopt the oxidation state of +3. They tend to be most stable at this state. Oxidation state is a calculated value used to show the number of electrons lost or gained.
What Is a Lanthanide?
Lanthanides are a family of 15 chemical elements whose atomic numbers range from 57 to 71. The 15 elements include: lanthanum (La), cerium (Ce), praseodymium, (Pr), neodymium (Nd), promethium (Pm), samarium (Sm), europium (Eu), gadolinium (Gd), terbium (Tb), dysprosium (Dy), holmium (Ho), erbium (Er), thulium (Tm), ytterbium (Yb), and lutetium (Lu).
Why are lanthanides corrosive?
They can tarnish when reacting with oxygen in the air. Other properties of lanthanides include their ability to be brittle or corrosive when interacting with other elements. Lanthanides are used for a wide variety of purposes, such as coloring ceramics, streetlights, and in glassware used to reduce glare.
What happens when you cut lanthanide?
For example, when you cut a lanthanide element, the silvery color you see will tarnish as the lanthanide element interacts with oxygen in the air. If a lanthanide element interacts with other elements, the properties of lanthanides can change.
What is the name of the mineral that was discovered in 1794?
An earth mineral ore called Gadolinite is discovered. Fast forward to 1794, and a scientist named Gadolin extracts the element yttria, later called yttrium, from this ore. In 1803, scientists Berzelius and Klaproth realize a different element called cerium could be extracted from the same ore.
How to know if lanthanides are lanthanides?
A great way to ensure you are looking at lanthanides is to pay attention to the first element in the row. You will see the first element in lanthanides has an atomic symbol of La. This also happens to be the first two letters in the name lanthanide. Hence, if you ever forget where the lanthanides are located, pay attention to the atomic symbol of La and you can't go wrong!
How many lanthanide elements were extracted from one ore?
Would you believe, over time, all 15 lanthanide elements were extracted and separated from this one ore? It's true! In fact, this method of discovery for lanthanide elements led to their classification as rare earth metals. This is plausible given their discovery in an earth mineral ore.
What are Lanthanides?
Lanthanides are the rare earth elements of the modern periodic table i .e. the elements with atomic numbers from 58 to 71 following the element Lanthanum. They are called rare earth metals since the occurrence of these elements is very small (3×10 -4 % of Earth’s crust). They are available in ‘monazite’ sand’ as lanthanide orthophosphates. The term ‘lanthanide’ was first introduced by the Norwegian mineralogist Victor Goldschmidt in the year 1925. The lanthanide family consists of fifteen metallic elements (from lanthanum to lutetium), all but one of which are f-block elements. The valence electrons of these elements lie in the 4f orbital. Lanthanum, however, is a d-block element with an electronic configuration of [Xe]5d 1 6s 2.
What is the melting point of lanthanides?
Like most metals, these elements have very high melting points (ranging from roughly 800 to 1600 degrees Celsius) and very high boiling points (ranging from roughly 1200 to 3500 degrees Celsius). All of the lanthanides are known to form Ln 3+ cations.
How many elements are in the lanthanide family?
The lanthanide family consists of fifteen metallic elements (from lanthanum to lutetium), all but one of which are f-block elements. The valence electrons of these elements lie in the 4f orbital. Lanthanum, however, is a d-block element with an electronic configuration of [Xe]5d 1 6s 2. The lanthanides are highly dense elements, ...
What is the oxidation state of lanthanide?
All the elements in the lanthanide series show an oxidation state of +3. Earlier it was believed that some of the metals (samarium, europium, and ytterbium) also show +2 oxidation states. Further studies on these metals and their compounds have revealed that all the metals in lanthanide series exhibit +2 oxidation state in their complexes in solutions.
Why does the atomic size of tri positive lanthanide decrease?
The atomic size or the ionic radii of tri positive lanthanide ions decrease steadily from La to Lu due to increasing nuclear charge and electrons entering inner (n-2) f orbital. This gradual decrease in the size with an increasing atomic number is called lanthanide contraction.
Why is the separation of lanthanides so difficult?
2. Difficulty in the separation of lanthanides: As there is an only small change in the ionic radii of Lanthanides, their chemical properties are similar. This makes the separation of elements in the pure state difficult.
Which oxidation state is the most stable?
Answer: In lanthanide series +2 oxidation state is the most stable state, as a result +2 oxidation state ion tend to loss one electron to form +3 oxidation state and the ions with +4 oxidation state, gains electron to become a stable ion. Test Your Knowledge On Lanthanides!
What makes lanthanide complexes effective?from en.wikipedia.org
Many of these features make lanthanide complexes effective catalysts. Hard Lewis acids are able to polarise bonds upon coordination and thus alter the electrophilicity of compounds, with a classic example being the Luche reduction. The large size of the ions coupled with their labile ionic bonding allows even bulky coordinating species to bind and dissociate rapidly, resulting in very high turnover rates; thus excellent yields can often be achieved with loadings of only a few mol%. The lack of orbital interactions combined with the lanthanide contraction means that the lanthanides change in size across the series but that their chemistry remains much the same. This allows for easy tuning of the steric environments and examples exist where this has been used to improve the catalytic activity of the complex and change the nuclearity of metal clusters.
What are lanthanides used for?from chem.libretexts.org
The lanthanides have many scientific and industrial uses. Their compounds are used as catalysts in the production of petroleum and synthetic products. Lanthanides are used in lamps, lasers, magnets, phosphors, motion picture projectors, and X-ray intensifying screens.
What is the melting point of lanthanide?from en.wikipedia.org
Gschneider and Daane (1988) attribute the trend in melting point which increases across the series, ( lanthanum (920 °C) – lutetium (1622 °C)) to the extent of hybridization of the 6s, 5d, and 4f orbitals. The hybridization is believed to be at its greatest for cerium, which has the lowest melting point of all, 795 °C. The lanthanide metals are soft; their hardness increases across the series. Europium stands out, as it has the lowest density in the series at 5.24 g/cm 3 and the largest metallic radius in the series at 208.4 pm. It can be compared to barium, which has a metallic radius of 222 pm. It is believed that the metal contains the larger Eu 2+ ion and that there are only two electrons in the conduction band. Ytterbium also has a large metallic radius, and a similar explanation is suggested. The resistivities of the lanthanide metals are relatively high, ranging from 29 to 134 μΩ·cm. These values can be compared to a good conductor such as aluminium, which has a resistivity of 2.655 μΩ·cm. With the exceptions of La, Yb, and Lu (which have no unpaired f electrons), the lanthanides are strongly paramagnetic, and this is reflected in their magnetic susceptibilities. Gadolinium becomes ferromagnetic at below 16 °C ( Curie point ). The other heavier lanthanides – terbium, dysprosium, holmium, erbium, thulium, and ytterbium – become ferromagnetic at much lower temperatures.
Why do lanthanides have strong magnetic fields?from chem.libretexts.org
Lanthanides exhibit strong electromagnetic and light properties because of the presence of unpaired electrons in the f-orbitals. The majority of the Lanthanides are paramagnetic, which means that they have strong magnetic fields.
Why is lanthanum called "rare earths"?from en.wikipedia.org
The "rare" in the "rare earths" name has much more to do with the difficulty of separating out each of the individual lanthanide elements than scarcity of any of them. By way of the Greek "dysprositos" for "hard to get at," element 66, dysprosium was similarly named; lanthanum itself is named after a word for "hidden.".
How much lanthanide is consumed?from en.wikipedia.org
Lanthanide elements and their compounds have many uses but the quantities consumed are relatively small in comparison to other elements. About 15000 ton/year of the lanthanides are consumed as catalysts and in the production of glasses. This 15000 tons corresponds to about 85% of the lanthanide production. From the perspective of value, however, applications in phosphors and magnets are more important.
How many atomic numbers does lanthanide have?from en.wikipedia.org
The lanthanide ( / ˈlænθənaɪd /) or lanthanoid ( / ˈlænθənɔɪd /) series of chemical elements comprises the 15 metallic chemical elements with atomic numbers 57–71, from lanthanum through lutetium. These elements, along with the chemically similar elements scandium and yttrium, are often collectively known as the rare-earth elements or rare-earth metals.
About Lanthanides
15 elements from Lanthanum (atomic number-57) to lutetium (atomic number-71) are called lanthanides. They include Lanthanum (La), Cerium (Ce), Praseodymium (Pr), Neodymium (Nd), Promethium (Pm), Samarium (Sm), Europium (Eu), Gadolinium (Gd), Terbium (Tb), Dysprosium (Dy), Holmium (Ho), Erbium (Er), Thulium (Tm), Ytterbium (Yb), Lutetium (Lu).
Properties of Lanthanides
Physical state: They are silvery white soft metals. Their hardness increase with increase in the atomic number, But samarium is exception here because they hard as steel.
Uses of Lanthanides
The uses of the compounds of lanthanides can broadly be classified follows:
Intro to Lanthanides
What are the lanthanides? The lanthanide series is a row of elements situated below the main block of the periodic table, within the f block along with the actinides. They are all metals. Lanthanides occupy elements 57-71 and branch off after barium on the periodic table.
Are the Rare Earth Elements Rare?
Rare earth elements are not particularly rare. Cerium is the 25th most abundant element in the earth’s crust, more common than copper.
How many Rare Earth Elements are there?
So how many rare earth elements actually exists? The answer is 15 or 17, depending on how you define a rare earth element. If you include Scandium and Yttrium, there are 17. If you don’t, and any include true lanthanides, than there are only 15 rare earths.
A List of Lanthanide Elements
The name Lanthanum comes from the Greek word Lanthanein, which means “hidden”. It was discovered by Swedish Chemist Carl Gustaf Masander in 1839. It is soft enough to be cut with a knife, ductile, and has a silvery color. Lanthanum has numerous industrial uses, including the ignition of torches, lighters, and blowpipes.
Conclusion on the Rare Earth Elements
Lanthanides are metallic elements that occupy positions 57-70 on the periodic table. When viewing the periodic table, they lie below the transition metals, and above the actinides.
Overview
Properties
- Bright and silvery in appearance, many of the lanthanidesthough they are metalsare so soft they can be cut with a knife. Lanthanum, cerium, praseodymium, neodymium, and europium are highly reactive. When exposed to oxygen, they form an oxide coating. (An oxide is a compound formed by metal with an oxygen.) To prevent this result, which tarnishes the metal, these five lanthanide…
Uses
- Among the applications for cerium is an alloy called misch metal, prepared by fusing the chlorides of cerium, lanthanum, neodymium, and praseodymium. The resulting alloy ignites at or below room temperature, and is often used as the \"flint\" in a cigarette lighter, because it sparks when friction from a metal wheel is applied. As with cerium, lanthanum is used in misch metal. Becau…
Chemistry
- In order to separate lanthanides from other elements, they are actually combined with other substancessubstances having a low solubility, or tendency to dissolve. Oxalates and fluorides are low-solubility substances favored for this purpose. Once they are separated from non-lanthanide elements, ion exchange is used to separate one lanthanide element from another.
Applications
- Possible medical uses
Currently there is research showing that lanthanide elements can be used as anticancer agents. The main role of the lanthanides in these studies is to inhibit proliferation of the cancer cells. Specifically cerium and lanthanum have been studied for their role as anti-cancer agen...
- Soft and malleable, with a lustrous silvery color, erbium produces salts (which are usually combinations of a metal with a nonmetal) that are pink and rose, making it useful as a tinting agent. One of its oxides is utilized, for instance, to tint glass and porcelain with a pinkish cast. It is also applied, to a limited extent, in the nuclear power industry.
Etymology
- Together with the two elements at the top of group 3, scandium and yttrium, the trivial name "rare earths" is sometimes used to describe all the lanthanides; a definition of rare earths including the group 3, lanthanide, and actinide elements is also occasionally seen, and rarely Sc + Y + lanthanides + thorium. The "earth" in the name "rare earths" arises from the minerals from which …
Distribution
- Though most of the lanthanides were first isolated in Scandinavia, today they are found in considerably warmer latitudes: Brazil, India, Australia, South Africa, and the United States. The principal source of lanthanides is monazite, a heavy, dark sand from which about 50% of the lanthanide mass available to science and industry has been extracted.
Structure
- The lanthanide series consists of the 14 elements, with atomic numbers 58 through 71, that follow lanthanum on the periodic table of elements. These 14, along with the actinidesatomic numbers 90 through 103are set aside from the periodic table due to similarities in properties that define each group. Specifically, the lanthanides and actinides are the only elements that fill the f …
Name
- Whereas many other lanthanides are named for regions in northern Europe, the name for europium refers to the European continent as a whole, and that of lutetium is a reference to the old Roman name for Paris. As mentioned earlier, Demarçay found europium in samarskite, a discovery he made in 1901. Actually, Boisbaudran had noticed what appeared to be a new eleme…
Literature
- \"Luminescent Lanthanides\" (Web site). <http://orgwww.chem.uva.nl/lanthanides/> (May 16, 2001). Snedden, Robert. Materials. Des Plaines, IL: Heinemann Library, 1999.
The D Block Elements
Lanthanide Uses
- The lanthanides have many scientific and industrial uses. Their compounds are used as catalysts in the production of petroleumand synthetic products. Lanthanides are used in lamps, lasers, magnets, phosphors, motion picture projectors, and X-ray intensifying screens. A pyrophoric mixed rare-earth alloy called Mischmetall (50% Ce, 25% La, 25% other light lanthanides) or misc…
Lanthanide Versus Lanthanoid
- Because the -ide suffix is used to indicate negative ions in chemistry, the IUPAC recommends members of this element group be called lanthanoids. The -oidsuffix is in keeping with names of another element group -- the metalloids. There is a precedent for a name change, since an even earlier name for the elements was "lanthanon." However, nearly all scientists and peer-reviewed …
Sources
- David A. Atwood, ed. (19 February 2013). The Rare Earth Elements: Fundamentals and Applications(eBook). John Wiley & Sons. ISBN 9781118632635.
- Gray, Theodore (2009). The Elements: A Visual Exploration of Every Known Atom in the Universe. New York: Black Dog & Leventhal Publishers. p. 240. ISBN 978-1-57912-814-2.
- Holden, Norman E.; Coplen, Tyler (2004). "The Periodic Table of the Elements". Chemistry Inte…
- David A. Atwood, ed. (19 February 2013). The Rare Earth Elements: Fundamentals and Applications(eBook). John Wiley & Sons. ISBN 9781118632635.
- Gray, Theodore (2009). The Elements: A Visual Exploration of Every Known Atom in the Universe. New York: Black Dog & Leventhal Publishers. p. 240. ISBN 978-1-57912-814-2.
- Holden, Norman E.; Coplen, Tyler (2004). "The Periodic Table of the Elements". Chemistry International. IUPAC. 26 (1): 8. doi:10.1515/ci.2004.26.1.8
- Krishnamurthy, Nagaiyar and Gupta, Chiranjib Kumar (2004). Extractive Metallurgy of Rare Earths. CRC Press. ISBN 0-415-33340-7
