Editing Lanthanide (section)

==Physical properties of the elements==
{| class="wikitable" style="margin:1em auto; font-size: 95%; text-align: center;"
|-
![[Chemical element]]!![[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]]
|-
| [[Atomic number]]
|57||58||59||60||61||62||63||64||65||66||67||68||69||70||71
|-
|Image|| [[File:Lanthanum-2.jpg|50px]]||[[File:Cerium2.jpg|50px]]||[[File:Praseodymium.jpg|50px]]||[[File:Neodymium2.jpg|50px]]||[[File:Promethium.png|50px]]||[[File:Samarium-2.jpg|50px]]||[[File:Europium.jpg|50px]]||[[File:Gadolinium-4.jpg|50px]]||[[File:Terbium-2.jpg|50px]]||[[File:Dy chips.jpg|50px]]||[[File:Holmium2.jpg|50px]]||[[File:Erbium-crop.jpg|50px]]||[[File:Thulium sublimed dendritic and 1cm3 cube.jpg|50px]]||[[File:Ytterbium-3.jpg|50px]]||[[File:Lutetium sublimed dendritic and 1cm3 cube.jpg|50px]]
|-
|Density (g/cm<sup>3</sup>)
|6.162||6.770||6.77||7.01||7.26||7.52||5.244||7.90||8.23||8.540||8.79||9.066||9.32||6.90||9.841
|-
|Melting point (°C)
|920||795||935||1024||1042||1072||826||1312||1356||1407||1461||1529||1545||824||1652
|-
|Boiling point (°C)
|3464||3443||3520||3074||3000||1794||1529||3273||3230||2567||2720||2868||1950||1196||3402
|-
| Atomic [[electron configuration]]<br> (gas phase)*||'''5d<sup>1</sup>'''||4f<sup>1</sup>'''5d<sup>1</sup>'''||4f<sup>3</sup>|| 4f<sup>4</sup>||4f<sup>5</sup>||4f<sup>6</sup>||4f<sup>7</sup>||4f<sup>7</sup>'''5d<sup>1</sup>'''||4f<sup>9</sup>||4f<sup>10</sup>||4f<sup>11</sup>||4f<sup>12</sup>||4f<sup>13</sup>||4f<sup>14</sup>||4f<sup>14</sup>'''5d<sup>1</sup>'''
|-
|Metal lattice (RT)
|dhcp||fcc||dhcp||dhcp||dhcp||**||bcc||hcp||hcp||hcp||hcp||hcp||hcp||fcc||hcp
|-
|Metallic radius (pm)
|162||181.8||182.4||181.4||183.4||180.4||208.4||180.4||177.3||178.1||176.2||176.1||175.9||193.3||173.8
|-
|Resistivity at 25&nbsp;°C (μΩ·cm)
|57–80<br>20&nbsp;°C||73||68||64||{{N/A}}||88||90||134||114||57||87||87||79||29||79
|-
|[[Magnetic susceptibility]]<br>χ<sub>mol</sub> /10<sup>−6</sup>(cm<sup>3</sup>·[[Mole (unit)|mol]]<sup>−1</sup>)
||+95.9||+2500 (β)||+5530 (α)||+5930 (α)||{{N/A}}||+1278 (α)||+30900||+185000<br>(350 K)||+170000 (α)||+98000||+72900||+48000||+24700||+67 (β)||+183
|}
<nowiki>*</nowiki> Between initial [[Xenon|Xe]] and final 6s<sup>2</sup> electronic shells

<nowiki>**</nowiki> Sm has a close packed structure like most of the lanthanides but has an unusual 9 layer repeat

Gschneider and Daane (1988) attribute the trend in melting point which increases across the series, ([[lanthanum]] (920&nbsp;°C) – lutetium (1622&nbsp;°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&nbsp;°C.<ref>Krishnamurthy, Nagaiyar and Gupta, Chiranjib Kumar (2004) ''Extractive Metallurgy of Rare Earths'', CRC Press, {{ISBN|0-415-33340-7}}</ref>
The lanthanide metals are soft; their hardness increases across the series.<ref name = "Greenwood&Earnshaw">{{Greenwood&Earnshaw2nd|pages=1230–1242}}</ref> Europium stands out, as it has the lowest density in the series at 5.24 g/cm<sup>3</sup> 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<sup>2+</sup> 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.<ref name = "Greenwood&Earnshaw"/>
The [[resistivity|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&nbsp;°C ([[Curie point]]). The other heavier lanthanides – terbium, dysprosium, holmium, erbium, thulium, and ytterbium – become ferromagnetic at much lower temperatures.<ref>Cullity, B. D. and Graham, C. D. (2011) ''Introduction to Magnetic Materials'', John Wiley & Sons, {{ISBN|9781118211496}}</ref>