Mendelevium (Md)
Mendelevium is the 101st element in the periodic table and has a symbol of Md and atomic number of 101. It has an atomic weight of (258) and a mass number of 244. Mendelevium has one hundred one protons and one hundred forty-three neutrons in its nucleus, and one hundred one electrons in seven shells. It is located in group Actinides, period seven and block f of the periodic table. Radioactive metallic transuranic element. Belongs to the actinoid series. Only known isotope, Md-256 has a half-life of 1.3 hours. First identified by Glenn T. Seaborg, Albert Ghiorso and associates in 1955. Alternative name Unnilunium has been proposed. Named after the 'inventor' of the periodic table, Dmitri Mendeleev.
| Atomic Number | 101 |
|---|---|
| Atomic Weight | 258 |
| Mass Number | 244 |
| Group | |
|---|---|
| Period | 7 |
| Block | f |
| Protons | 101 p+ |
|---|---|
| Neutrons | 143 n0 |
| Electrons | 101 e- |
Properties
| Physical Properties | |
|---|---|
| Atomic Radius | |
| Molar Volume | |
| Covalent Radius | 173 pm
|
| Metallic Radius | |
| Ionic Radius | 109.5 pm
|
| Crystal Radius | 123.5 pm
|
| Van der Waals Radius |
246 pm
|
| Density | 10.3 g/cm³
|
| Energy | |
| Proton Affinity | |
| Electron Affinity | |
| Ionization Energy | 6.58 eV/particle
|
| Heat of Vaporization | |
| Heat of Fusion | |
| Heat of Formation | |
| Electrons | |
| Electron Shells | 2, 8, 18, 32, 31, 8, 2 |
 | |
| Valence Electrons | 2 ⓘ |
 | |
| Electron Configuration | [Rn] 5f13 7s2ⓘ 1s2 2s2 2p6 3s2 3p6 4s2 3d10 4p6 5s2 4d10 5p6 6s2 4f14 5d10 6p6 5f13 7s2 |
  | |
| Oxidation States | 2, 3 |
| Electronegativity | |
| Electrophilicity Index | |
| States of Matter | |
| Phase | Solid |
| Gas Phase | |
| Boiling Point | |
| Melting Point | 1,100.15 K
|
| Critical Pressure | |
| Critical Temperature | |
| Triple Point | |
| Visual | |
Mendelevium is a Colorless. Md has a CPK of #ffffff, Jmol of #b30da6, and MOLCAS GV of #b30da6. | |
| Color | Colorless
|
| Appearance | |
| Refractive Index | |
| Thermodynamic Properties | |
| Thermal Conductivity | |
| Thermal Expansion | |
| Molar Heat Capacity | |
| Specific Heat Capacity | |
| Heat Capacity Ratio (Adiabatic Index) | |
| Electrical Properties | |
| Type | |
| Electrical Conductivity | |
| Electrical Resistivity | |
| Superconducting Point | |
| Magnetism | |
| Type | |
| Magnetic Susceptibility (Mass) | |
| Magnetic Susceptibility (Molar) | |
| Magnetic Susceptibility (Volume) | |
| Magnetic Ordering | |
| Curie Point | |
| Neel Point | |
| Structure | |
The lattice angles of Mendelevium is . | |
| Crystal Structure | () |
| Lattice Constant | |
| Lattice Angles | |
| Mechanical Properties | |
| Hardness | |
| Bulk Modulus | |
| Shear Modulus | |
| Young's Modulus | |
| Poisson Ratio | |
| Speed of Sound | |
| Classification | |
The Glawe Number of Mendelevium is 45. The Mendeleev Number of Md is 38. The Pettifor Number of Element 101 is 36. The Goldschmidt Class of Mendelevium (Md) is synthetic. | |
| Category | Actinides, Actinides |
| CAS Group | |
| IUPAC Group | |
| Glawe Number | 45 |
| Mendeleev Number | 38 |
| Pettifor Number | 36 |
| Geochemical Class | |
| Goldschmidt Class | synthetic |
| Other | |
The Dipole Polarizability of Mendelevium is 109 plus or minus 20 a₀. The Allotropes of Md is . The Quantum Numbers of Element 101 is 2F7/2. The Space Group of Mendelevium (Md) is (). | |
| Gas Basicity | |
| Dipole Polarizability | |
| C6 Dispersion Coefficient | |
| Allotropes | |
| Neutron Cross Section | |
| Neutron Mass Absorption | |
| Quantum Numbers | 2F7/2 |
| Space Group | () |
Isotopes of Mendelevium
| Stable Isotopes | 0 |
|---|---|
| Unstable Isotopes | 19 |
| Radioactive Isotopes | 19 |
244Md
| Mass Number | 244 |
|---|---|
| Neutron Number | 143 |
| Relative Atomic Mass | |
| G-Factor | |
| Abundance | |
| Radioactivity | ☢️ Radioactive |
| Half Life | 0.36 ± 0.14 s
|
| Spin | 3 |
| Quadrupole Moment | |
| Discovery Year | 2020 |
| Parity | + |
| Decay Mode | Intensity |
|---|---|
| α (α emission) | 100% |
| β+ (β+ decay; β+ = ϵ + e+) | |
| β+ SF (β+-delayed fission) | 14% |
245Md
| Mass Number | 245 |
|---|---|
| Neutron Number | 144 |
| Relative Atomic Mass | |
| G-Factor | |
| Abundance | |
| Radioactivity | ☢️ Radioactive |
| Half Life | 0.38 ± 0.1 s
|
| Spin | 7/2 |
| Quadrupole Moment | |
| Discovery Year | 1996 |
| Parity | - |
| Decay Mode | Intensity |
|---|---|
| α (α emission) | 100% |
| β+ (β+ decay; β+ = ϵ + e+) |
246Md
| Mass Number | 246 |
|---|---|
| Neutron Number | 145 |
| Relative Atomic Mass | |
| G-Factor | |
| Abundance | |
| Radioactivity | ☢️ Radioactive |
| Half Life | 0.92 ± 0.18 s
|
| Spin | 1 |
| Quadrupole Moment | |
| Discovery Year | 1996 |
| Parity | - |
| Decay Mode | Intensity |
|---|---|
| α (α emission) | 100% |
247Md
| Mass Number | 247 |
|---|---|
| Neutron Number | 146 |
| Relative Atomic Mass | |
| G-Factor | |
| Abundance | |
| Radioactivity | ☢️ Radioactive |
| Half Life | 1.19 ± 0.09 s
|
| Spin | 7/2 |
| Quadrupole Moment | |
| Discovery Year | 1981 |
| Parity | - |
| Decay Mode | Intensity |
|---|---|
| α (α emission) | 100% |
| SF (spontaneous fission) | 0.1% |
248Md
| Mass Number | 248 |
|---|---|
| Neutron Number | 147 |
| Relative Atomic Mass | |
| G-Factor | |
| Abundance | |
| Radioactivity | ☢️ Radioactive |
| Half Life | 7 ± 3 s
|
| Spin | |
| Quadrupole Moment | |
| Discovery Year | 1973 |
| Parity |
| Decay Mode | Intensity |
|---|---|
| β+ (β+ decay; β+ = ϵ + e+) | 80% |
| α (α emission) | 20% |
| β+ SF (β+-delayed fission) | 0.05% |
249Md
| Mass Number | 249 |
|---|---|
| Neutron Number | 148 |
| Relative Atomic Mass | |
| G-Factor | |
| Abundance | |
| Radioactivity | ☢️ Radioactive |
| Half Life | 25.6 ± 0.9 s
|
| Spin | 7/2 |
| Quadrupole Moment | |
| Discovery Year | 1973 |
| Parity | - |
| Decay Mode | Intensity |
|---|---|
| α (α emission) | 75% |
| β+ (β+ decay; β+ = ϵ + e+) |
250Md
| Mass Number | 250 |
|---|---|
| Neutron Number | 149 |
| Relative Atomic Mass | |
| G-Factor | |
| Abundance | |
| Radioactivity | ☢️ Radioactive |
| Half Life | 54 ± 4 s
|
| Spin | 2 |
| Quadrupole Moment | |
| Discovery Year | 1973 |
| Parity | - |
| Decay Mode | Intensity |
|---|---|
| β+ (β+ decay; β+ = ϵ + e+) | 93% |
| α (α emission) | 7% |
| β+ SF (β+-delayed fission) | 0.026% |
251Md
| Mass Number | 251 |
|---|---|
| Neutron Number | 150 |
| Relative Atomic Mass | |
| G-Factor | |
| Abundance | |
| Radioactivity | ☢️ Radioactive |
| Half Life | 4.21 ± 0.23 m
|
| Spin | 7/2 |
| Quadrupole Moment | |
| Discovery Year | 1973 |
| Parity | - |
| Decay Mode | Intensity |
|---|---|
| β+ (β+ decay; β+ = ϵ + e+) | |
| α (α emission) | 10% |
252Md
| Mass Number | 252 |
|---|---|
| Neutron Number | 151 |
| Relative Atomic Mass | |
| G-Factor | |
| Abundance | |
| Radioactivity | ☢️ Radioactive |
| Half Life | 2.3 ± 0.8 m
|
| Spin | 1 |
| Quadrupole Moment | |
| Discovery Year | 1973 |
| Parity | + |
| Decay Mode | Intensity |
|---|---|
| β+ (β+ decay; β+ = ϵ + e+) | 100% |
| α (α emission) |
253Md
| Mass Number | 253 |
|---|---|
| Neutron Number | 152 |
| Relative Atomic Mass | |
| G-Factor | |
| Abundance | |
| Radioactivity | ☢️ Radioactive |
| Half Life | 12 ± 8 m
|
| Spin | 7/2 |
| Quadrupole Moment | |
| Discovery Year | 1992 |
| Parity | - |
| Decay Mode | Intensity |
|---|---|
| β+ (β+ decay; β+ = ϵ + e+) | 100% |
| α (α emission) | 0.7% |
254Md
| Mass Number | 254 |
|---|---|
| Neutron Number | 153 |
| Relative Atomic Mass | |
| G-Factor | 0
|
| Abundance | |
| Radioactivity | ☢️ Radioactive |
| Half Life | 10 ± 3 m
|
| Spin | 0 |
| Quadrupole Moment | 0
|
| Discovery Year | 1970 |
| Parity | - |
| Decay Mode | Intensity |
|---|---|
| β+ (β+ decay; β+ = ϵ + e+) | 100% |
| α (α emission) |
255Md
| Mass Number | 255 |
|---|---|
| Neutron Number | 154 |
| Relative Atomic Mass | |
| G-Factor | |
| Abundance | |
| Radioactivity | ☢️ Radioactive |
| Half Life | 27 ± 2 m
|
| Spin | 7/2 |
| Quadrupole Moment | |
| Discovery Year | 1958 |
| Parity | - |
| Decay Mode | Intensity |
|---|---|
| β+ (β+ decay; β+ = ϵ + e+) | 93% |
| α (α emission) | 7% |
| SF (spontaneous fission) |
256Md
| Mass Number | 256 |
|---|---|
| Neutron Number | 155 |
| Relative Atomic Mass | |
| G-Factor | |
| Abundance | |
| Radioactivity | ☢️ Radioactive |
| Half Life | 77.7 ± 1.8 m
|
| Spin | 1 |
| Quadrupole Moment | |
| Discovery Year | 1955 |
| Parity | - |
| Decay Mode | Intensity |
|---|---|
| β+ (β+ decay; β+ = ϵ + e+) | 90.8% |
| α (α emission) | 9.2% |
| SF (spontaneous fission) | 3% |
257Md
| Mass Number | 257 |
|---|---|
| Neutron Number | 156 |
| Relative Atomic Mass | |
| G-Factor | |
| Abundance | |
| Radioactivity | ☢️ Radioactive |
| Half Life | 5.52 ± 0.05 h
|
| Spin | 7/2 |
| Quadrupole Moment | |
| Discovery Year | 1965 |
| Parity | - |
| Decay Mode | Intensity |
|---|---|
| ϵ (electron capture) | 85% |
| α (α emission) | 15% |
| SF (spontaneous fission) |
258Md
| Mass Number | 258 |
|---|---|
| Neutron Number | 157 |
| Relative Atomic Mass | |
| G-Factor | |
| Abundance | |
| Radioactivity | ☢️ Radioactive |
| Half Life | 51.59 ± 0.29 d
|
| Spin | 8 |
| Quadrupole Moment | |
| Discovery Year | 1970 |
| Parity | - |
| Decay Mode | Intensity |
|---|---|
| α (α emission) | 100% |
| β+ (β+ decay; β+ = ϵ + e+) | 0.0015% |
| β− (β− decay) | 0.0015% |
259Md
| Mass Number | 259 |
|---|---|
| Neutron Number | 158 |
| Relative Atomic Mass | |
| G-Factor | |
| Abundance | |
| Radioactivity | ☢️ Radioactive |
| Half Life | 1.6 ± 0.06 h
|
| Spin | 7/2 |
| Quadrupole Moment | |
| Discovery Year | 1982 |
| Parity | - |
| Decay Mode | Intensity |
|---|---|
| SF (spontaneous fission) | 100% |
| α (α emission) |
260Md
| Mass Number | 260 |
|---|---|
| Neutron Number | 159 |
| Relative Atomic Mass | |
| G-Factor | |
| Abundance | |
| Radioactivity | ☢️ Radioactive |
| Half Life | 27.8 ± 0.8 d
|
| Spin | |
| Quadrupole Moment | |
| Discovery Year | 1989 |
| Parity |
| Decay Mode | Intensity |
|---|---|
| SF (spontaneous fission) | 100% |
| α (α emission) | 5% |
| ϵ (electron capture) | 5% |
| β− (β− decay) | 3.5% |
261Md
| Mass Number | 261 |
|---|---|
| Neutron Number | 160 |
| Relative Atomic Mass | |
| G-Factor | |
| Abundance | |
| Radioactivity | ☢️ Radioactive |
| Half Life | |
| Spin | 7/2 |
| Quadrupole Moment | |
| Discovery Year | |
| Parity | - |
| Decay Mode | Intensity |
|---|---|
| α (α emission) |
262Md
| Mass Number | 262 |
|---|---|
| Neutron Number | 161 |
| Relative Atomic Mass | |
| G-Factor | |
| Abundance | |
| Radioactivity | ☢️ Radioactive |
| Half Life | |
| Spin | |
| Quadrupole Moment | |
| Discovery Year | |
| Parity |
| Decay Mode | Intensity |
|---|---|
| SF (spontaneous fission) | |
| α (α emission) |
History
Mendelevium was discovered by Albert Ghiorso, Glenn T. Seaborg, Gregory R. Choppin, Bernard G. Harvey and Stanley G. Thompson in 1955 at the University of California, Berkeley. It was produced by the bombardment of einsteinium with helium. Mendelevium was identified by chemical analysis in an ion exchange experiment. Named after Dmitri Mendeleev, who created the Periodic Table
| Discoverers | G.T.Seaborg, S.G.Tompson, A.Ghiorso, K.Street Jr. |
|---|---|
| Discovery Location | United States |
| Discovery Year | 1955 |
| Etymology (Name Origin) | Named in honor of the scientist Dmitri Ivanovitch Mendeleyev, who devised the periodic table. |
| Pronunciation | men-deh-LEE-vi-em (English) |
Mendelevium is harmful due to its radioactivity
Mendelevium was the first element to be produced one atom at a time
Uses
Mendelevium is used for scientific research purposes only. It has no significant commercial applications.
Sources
Made by bombarding einsteinium with helium ions.
| Abundance | |
|---|---|
| Abundance in Earth's crust | |
| Natural Abundance (Oceans) | |
| Natural Abundance (Human Body) | 0 %
|
| Natural Abundance (Meteor) | 0 %
|
| Natural Abundance (Sun) | 0 %
|
| Abundance in Universe | 0 %
|
Nuclear Screening Constants
Also Known As
- Md
- element 101
- Unu
- unnilunium
- 101Md
- Mv
Translations
- Frenchmendélévium
- GermanMendelevium
- Amharicሜንደሊቭየም
- Arabicمندليفيوم
- AzerbaijaniMendeleyevum
- BelarusianМендзялевій
- Bulgarianменделевий
- Banglaমেন্ডেলেভিয়াম
- Bosnianmendelevij
- Catalanmendelevi
- CorsicanMendeleviu
- Czechmendelevium
- ChuvashМенделеви
- WelshMendelefiwm
- Danishmendelevium
- Greekμεντελέβιο
- Esperantomendelevio
- Spanishmendelevio
- Estonianmendeleevium
- Basquemendelevio
- Persianمندلیفیم
- Finnishmendelevium
- FriulianMendelevi
- Irishmeindiléiviam
- Galicianmendelevio
- ManxMendelevium
- Hakka Chinesemendelevium
- Hebrewמנדלביום
- Fiji HindiMendelevium
- Croatianmendelevij
- Hungarianmendelévium
- Armenianմենդելևիում
- Interlinguamendelevium
- Indonesianmendelevium
- Idomendelevio
- Italianmendelevio
- Japaneseメンデレビウム
- Lojbanjinmrmendelevi
- JavaneseMendelevium
- Kannadaಮೆಂಡೆಲೀವಿಯಮ್
- Korean멘델레븀
- KomiМенделевий
- Latinmendelevium
- LuxembourgishMendelevium
- LigurianMendelevio
- Lithuanianmendelevis
- Latvianmendeļejevijs
- Malayalamമെൻഡെലീവിയം
- Marathiमेंडेलेवियम
- Western MariМенделевий
- MalayMendelevium
- Burmeseမန်ဒယ်လီဗီယမ်
- Dutchmendelevium
- Norwegian Nynorskmendelevium
- Polishmendelew
- Portuguesemendelévio
- QuechuaMendelewyu
- Romanianmendeleviu
- Russianменделевий
- SakhaМенделевиум
- Sicilianmindileviu
- Serbo-CroatianMendeljejevijum
- Slovakmendelevium
- Slovenianmendelevij
- Serbianмендељејевијум
- Saterland FrisianMendelevium
- Swedishmendelevium
- Thaiเมนเดลีเวียม
- Turkishmendelevyum
- Uyghurمېندېلېيېۋىي
- Ukrainianменделєвій
- Urdumendelevium
- VepsMendelevii
- VietnameseMendelevi
- WarayMendelevyo
- KalmykМенделевиүм
- YorubaMẹ̀ndẹ̀lẹ́fíọ̀m
- Chinese钔
- English (Canada)Mendelevium
- English (United Kingdom)mendelevium
- Chinese (China)钔
- Chinese (Simplified)钔
- Chinese (Traditional)鍆
- Norwegian Bokmålmendelevium
- CebuanoMendelevyo
- Macedonianменделевиум
- Central Kurdishمەندەلیێڤیۆم
- pnbمینڈلیوئیم
- BretonMendeleviom
- KazakhМенделевий
- Gujaratiમેન્ડેલિવીયમ
- Odiaମେଡ଼େଲିଭିଅମ
- TatarМенделевий
- PiedmonteseMendelevi
- Hindiमेण्डेलीवियम
- Newariमेन्डेलेभियम
- AlbanianMendeleviumi
- Cantonese鍆
- Tamilமெண்டலீவியம்
- UzbekMendeleviy
- Chinese (Hong Kong SAR China)鍆
- Chinese (Taiwan)鍆
- AromanianMendeleviu
- Sanskritमेन्डेलेभियम
- Nepaliमेन्देलिभियम
- Maltesemendelevju
- KyrgyzМенделеевий
- Georgianმენდელევიუმი
- Scottish GaelicMendelevium
- Teluguమెండలీవియం
- LimburgishMendelevium
- cdoMendelevium
- Min Nan ChineseMendelevium
- AsturianMendeleviu
- Belarusian (Taraskievica orthography)Мендзялеў
- Bhojpuriमेंडेलेवियम
- Chinese (Macao SAR China)鍆
- Chinese (Malaysia)钔
- Chinese (Singapore)钔
- Portuguese (Brazil)mendelévio
- Paliमेन्डेलेभियम
- Lingua Franca Novamendelevio
- TagalogMendelebiyo
- AfrikaansMendelevium
- kbpMɛndɛlɛvɩyɔm
- Literary Chinese鍆
- Northern FrisianMendeleewium
- Volapükmendelevin
- oloMendelevii
- TajikМенделевий
- IcelandicMendelevín
- Mongolianменделеви
- SardinianMendelèviu
- Wu Chinese钔
- Moroccan Arabicمينديلييڤيوم
- Pashtoمندليفيوم
- Egyptian Arabicمندليفيوم
- CornishMendeleviom
- Manipuriꯃꯦꯟꯗꯦꯂꯦꯚꯤꯌꯝ
- BalineseMéndelevium
