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Element 101 · Mendelevium (Md)

Mendelevium Bohr model: diagram and electrons per shell

The mendelevium Bohr model shows a mendelevium atom (Md) as a small nucleus with its electrons circling it in 7 shells: 2 in shell K, 8 in shell L, 18 in shell M, 32 in shell N, 31 in shell O, 8 in shell P and 2 in shell Q. This page has a rotating 3D mendelevium Bohr model, a flat diagram, a table of the electrons in each shell and the steps to draw it yourself.

Rotate the mendelevium Bohr model in 3D

Drag to orbit, scroll to zoom.

This is a Bohr model of mendelevium (Md), a simplified picture of a single mendelevium atom. Its nucleus holds 101 protons, and a neutral mendelevium atom has 101 electrons, arranged around it in 7 shells (2 in shell K, 8 in shell L, 18 in shell M, 32 in shell N, 31 in shell O, 8 in shell P and 2 in shell Q).

Md K · 21s2 L · 82s2 2p6 M · 183s2 3p6 3d10 N · 324s2 4p6 4d10 4f14 O · 315s2 5p6 5d10 5f13 P · 86s2 6p6 Q · 27s2

Mendelevium Bohr model diagram

Bohr model diagram of mendelevium: a nucleus of 101 protons with 101 electrons on 7 shells, 2 in shell K, 8 in shell L, 18 in shell M, 32 in shell N, 31 in shell O, 8 in shell P and 2 in shell Q, each ring labelled with its shell letter.
The mendelevium Bohr model drawn flat: each ring is a shell, labelled with its letter, and every dot is an electron (2 in shell K, 8 in shell L, 18 in shell M, 32 in shell N, 31 in shell O, 8 in shell P and 2 in shell Q).

Mendelevium electrons per shell

A neutral mendelevium atom has 101 electrons, one for each of its 101 protons. They fill the shells from the nucleus outwards: 2 in shell K, 8 in shell L, 18 in shell M, 32 in shell N, 31 in shell O, 8 in shell P and 2 in shell Q.

Electrons in each shell of the mendelevium Bohr model
ShellShell number (n)ElectronsMost it can hold (2n²)Subshells
K1221s2
L2882s2 2p6
M318183s2 3p6 3d10
N432324s2 4p6 4d10 4f14
O531505s2 5p6 5d10 5f13
P68726s2 6p6
Q72987s2

How the mendelevium Bohr model builds up, shell by shell

Watch the mendelevium Bohr model come together: the nucleus first, then each shell in turn, from the innermost outwards, with its electrons joining the ring. The legend names every shell and counts its electrons, so you can read off the arrangement (2 in shell K, 8 in shell L, 18 in shell M, 32 in shell N, 31 in shell O, 8 in shell P and 2 in shell Q) as it forms.

Animation of the mendelevium Bohr model being built: a nucleus of 101 protons appears first, then each shell grows in around it and takes its electrons, giving 101 electrons on 7 shells (2 in shell K, 8 in shell L, 18 in shell M, 32 in shell N, 31 in shell O, 8 in shell P and 2 in shell Q).
The mendelevium Bohr model built up in six seconds: the nucleus first, then each shell with its electrons, ending with 2 in shell K, 8 in shell L, 18 in shell M, 32 in shell N, 31 in shell O, 8 in shell P and 2 in shell Q. Protons are red, neutrons yellow and electrons blue.

How to draw the mendelevium Bohr model

  1. Find the atomic number. Mendelevium has atomic number 101, so a neutral atom has 101 protons and 101 electrons.
  2. Draw the nucleus. Put a circle in the centre and write Md in it. The 101 protons sit there with the neutrons.
  3. Draw the shells. Sketch 7 shells as rings around the nucleus. A shell holds at most 2n² electrons: 2 in the first, 8 in the second, 18 in the third and 32 in the fourth.
  4. Place the electrons. Fill from the inside out: 2 in shell K, 8 in shell L, 18 in shell M, 32 in shell N, 31 in shell O, 8 in shell P and 2 in shell Q.
  5. Check the total. 2 + 8 + 18 + 32 + 31 + 8 + 2 = 101, the atomic number, so every electron is accounted for.

Atomic data for the mendelevium Bohr model

The numbers behind the mendelevium Bohr model, grouped by topic. Radii are in picometres (pm) and energies in kilojoules per mole (kJ/mol).

Identity

Symbol
Md
Atomic number
101
Atomic mass
[258] u
Family
Actinides
Position
period 7 of the f-block
Block
f-block

Electron configuration

Full
1s2 2s2 2p6 3s2 3p6 4s2 3d10 4p6 5s2 4d10 5p6 6s2 4f14 5d10 6p6 7s2 5f13
Shorthand
[Rn] 5f13 7s2
Electrons per shell
2, 8, 18, 32, 31, 8, 2
Outer-shell electrons
2 in shell Q

Ionisation energies

I₁
635

Energy to remove each electron in turn (kJ/mol). A sharp jump means the next electron comes from an inner shell.

Electronegativity and electron affinity

Electronegativity (Pauling)
1.3
Electron affinity (kJ/mol)
93.91

Oxidation states

+3

Charges the element commonly takes in compounds.

Physical properties, abundance and history of mendelevium

Bulk properties of mendelevium, how common it is, who discovered it and some of its compounds.

Physical properties

Phase at room conditions
Solid
Melting point
826.85°C (1100 K)

Discovery

Discovered by
Lawrence Berkeley National Laboratory
Year
1955

Common compounds

  • Mendelevium Md
  • Mendelevium-257 Md
  • Mendelevium, isotope of mass 258 Md
  • Acetaldehyde;mendelevium;3-[6-methyl-1-[2-methyl-4-(trifluoromethyl)benzene-5-id-1-yl]octan-3-yl]-1,2-oxazol-5-amine C22H30F3MdN2O2-
  • (2R)-2-[[1-[4-(dimethylamino)-4-methylpent-2-ynoyl]azetidin-3-yl]oxymethyl]-N-[(16S,22S)-12,12-dimethyl-15,21-dioxo-10-sulfanylidene-33-(2,2,2-trifluoroethyl)-14-oxa-25-thia-8,20,33,34,35-pentazaheptacyclo[26.3.1.13,31.116,20.124,27.02,11.04,9]pentatriaconta-1(31),2,4(9),5,7,24(34),26,28(32),29-nonaen-22-yl]-3-methylbutanamide;mendelevium C49H57F3MdN8O6S2
  • 3-[2-(2,4-dimethyl-5-pyridin-4-ylthiophen-3-yl)-3,3,4,4,5,5-hexafluorocyclopenten-1-yl]-2-ethyl-N-methyl-1-benzothiophen-6-amine;mendelevium C27H21F6MdN2S2-
  • Cyclohexane;1,2-difluoro-3-methanidylbenzene-6-ide;gadolinium;mendelevium;rhenium;rutherfordium C13H14F2GdMdReRf-4
  • 4-(5-dimethylphosphorylfuran-2-yl)-N,N-dimethyl-5H-1,3-thiazol-5-id-2-amine;mendelevium C11H14MdN2O2PS-

Compounds listed in the PubChem database.

Main isotopes of mendelevium

Isotopes of mendelevium share the same 101 protons but differ in neutrons. Natural isotopes come first, then the longest-lived others.

Main isotopes of mendelevium: mass number, abundance, half-life and decay
Mass numberNatural abundanceHalf-lifeDecay
255–27 minβ⁺, α, SF
256–77.7 minβ⁺, α, SF
257–5.52 hEC, α, SF
258–51.59 dα, β⁺, β⁻
259–1.6 hSF, α
260–27.8 dSF, α, EC, β⁻

α = alpha decay, β⁻ = beta-minus, β⁺ = beta-plus, EC = electron capture, SF = spontaneous fission, p / n = proton / neutron emission.

More about mendelevium