103LrLawrencium266[Rn] 5f¹⁴ 7s² 7p¹
actinide

Lawrencium

Lawrencium is a synthetic chemical element with chemical symbol Lr (formerly Lw) and atomic number 103. It is named in honor of Ernest Lawrence, inventor of the cyclotron, a device that was used to discover many artificial radioactive elements. A radioactive metal, lawrencium is the eleventh transuranic element and is also the final member of the actinide series.

Properties

At a glance

Atomic number
103
Atomic mass
266 u
Phase
Solid
Density
Unavailable
Melting point
1,900 K
Boiling point
Unavailable
First ionization energy
478.6 kJ/mol
Electronegativity
1.3
Electron affinity
-30.04 kJ/mol
Molar heat capacity
Unavailable
Period
7
Appearance
Unavailable

Conditions and isotopes affect measured properties. Some properties of short-lived elements are predicted. Electronegativity uses the Pauling scale.

Electronic structure

Lawrencium’s orbitals use a hydrogen-like approximation. Every orbital of each visible subshell is shown: in Shapes as the surface holding half its probability, with light and dark shades for opposite signs of the wavefunction; in Cloud as dots where its electrons are likely to be. Sizes are stepped by shell, like the Shell model.

Electrons by shell
Electron configuration

86 is the [Rn] core total across six shells.

Preparing the orbital view…

103 protons161 neutrons

Lawrencium-264: its most common form in nature, or its longest-lived if it has none. The nucleus is drawn far too big: it’s about 100,000 times smaller than the atom.

Ionization energy

Pull the electrons off

Lr

LrNeutral atom · no charge

A neutral lawrencium atom. Removing its first electron takes 479 kJ/mol.

Lawrencium’s outer shell holds 3 electrons. Electron 4 is the first from an inner shell: it sits closer to the nucleus with less shielding, so removing it takes 2× as much energy as the one before. Each dashed line on the chart marks another jump, into a shell even closer to the nucleus.

Shell 1Shell 2Shell 3Shell 4Shell 5Shell 6Shell 7MeasuredEstimated or calculatedEnergy in kJ/molkJ/mol (kilojoules per mole) is the energy to remove that electron from every atom in a mole of them: about 602 sextillion (6.02 × 10²³) atoms. For a single atom, divide by 96.485 to get electronvolts (eV). Lawrencium’s first electron takes about 5 eV.
1001,00010,000100,0001,000,00010,000,000100,000,000Shell 5Shell 4Shell 3×2×1.1×1.1×1.6×2×3.915101520253035404550556065707580859095100
Show the values as a table
ElectronShellEnergy (kJ/mol)× previousValue
17479–Measured
271,4032.9Calculated
372,1031.5Calculated
464,2072Estimated
565,4031.3Calculated
667,7191.4Calculated
769,2631.2Calculated
8611,6751.3Calculated
9613,7971.2Calculated
10615,9201.2Calculated
11619,0081.2Calculated
12520,8411.1Calculated
13523,5421.1Calculated
14525,9551.1Calculated
15527,9811.1Calculated
16531,0681.1Calculated
17533,1911.1Calculated
18536,0861.1Calculated
19538,8841.1Calculated
20541,5851.1Calculated
21544,2871.1Calculated
22546,9881.1Calculated
23549,2081Calculated
24552,1021.1Calculated
25554,0321Calculated
26571,8821.3Calculated
27575,1621Calculated
28578,5391Calculated
29582,2061Calculated
30585,6791Calculated
31588,9591Calculated
32595,0381.1Calculated
33598,4151Calculated
345102,3711Calculated
355105,9411Calculated
365123,5011.2Calculated
375127,3611Calculated
385131,2201Calculated
395136,0441Calculated
405151,4821.1Calculated
415156,3061Calculated
425169,8141.1Calculated
435174,6381Calculated
444193,9361.1Calculated
454202,6191Calculated
464211,3031Calculated
474220,9511Calculated
484229,6351Calculated
494238,3191Calculated
504247,9671Calculated
514257,6161Calculated
524268,2291Calculated
534275,9481Calculated
544285,5971Calculated
554295,2451Calculated
564303,9291Calculated
574313,5771Calculated
584360,9521.2Calculated
594368,6701Calculated
604376,8721Calculated
614385,5551Calculated
624393,8531Calculated
634401,8611Calculated
644420,6761Calculated
654429,1671Calculated
664438,0431Calculated
674446,7271Calculated
684481,4621.1Calculated
694489,1811Calculated
704497,8641Calculated
714506,5481Calculated
724571,1931.1Calculated
734581,8071Calculated
744606,8931Calculated
754616,5411Calculated
763957,1341.6Calculated
773975,4671Calculated
783994,7641Calculated
7931,015,0261Calculated
8031,034,3231Calculated
8131,053,6201Calculated
8231,106,6871.1Calculated
8331,126,9491Calculated
8431,149,1401Calculated
8531,169,4021Calculated
8631,226,3291Calculated
8731,243,6961Calculated
8831,262,9931Calculated
8931,283,2551Calculated
9031,476,2261.2Calculated
9131,505,1711Calculated
9231,543,7651Calculated
9331,563,0621Calculated
9423,126,1252Calculated
9523,174,3671Calculated
9623,222,6101Calculated
9723,270,8531Calculated
9824,013,7901.2Calculated
9924,081,3301Calculated
10024,168,1661Calculated
10124,222,1021Calculated
102116,413,6993.9Calculated
103116,685,0161Calculated

Successive ionization energies of gas-phase atoms and ions from the NIST Atomic Spectra Database. Solid bars are measured; hatched bars were estimated from nearby measurements or calculated from quantum theory, as is usual for highly charged ions. Electrons are taken from the outermost shell first, a simplification: electrons in different subshells of the same shell also differ in energy. On the log scale each gridline is 10 times the one below.

Keep exploring

Explore the stories, imagery, and reference data in more depth. Properties with no value in the reference are marked unavailable.