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Element 3 · Lithium (Li)

Lithium Bohr model: diagram and electrons per shell

The lithium Bohr model shows a lithium atom (Li) as a small nucleus with its electrons circling it in 2 shells: 2 in shell K and 1 in shell L. This page has a rotating 3D lithium Bohr model, a flat diagram, a table of the electrons in each shell and the steps to draw it yourself.

Rotate the lithium Bohr model in 3D

Drag to orbit, scroll to zoom.

This is a Bohr model of lithium (Li), a simplified picture of a single lithium atom. Its nucleus holds 3 protons, and a neutral lithium atom has 3 electrons, arranged around it in 2 shells (2 in shell K and 1 in shell L).

Li K · 21s2 L · 12s1

Lithium Bohr model diagram

Bohr model diagram of lithium: a nucleus of 3 protons with 3 electrons on 2 shells, 2 in shell K and 1 in shell L, each ring labelled with its shell letter.
The lithium Bohr model drawn flat: each ring is a shell, labelled with its letter, and every dot is an electron (2 in shell K and 1 in shell L).

Lithium electrons per shell

A neutral lithium atom has 3 electrons, one for each of its 3 protons. They fill the shells from the nucleus outwards: 2 in shell K and 1 in shell L.

Electrons in each shell of the lithium Bohr model
ShellShell number (n)ElectronsMost it can hold (2n²)Subshells
K1221s2
L2182s1

How the lithium Bohr model builds up, shell by shell

Watch the lithium 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 and 1 in shell L) as it forms.

Animation of the lithium Bohr model being built: a nucleus of 3 protons appears first, then each shell grows in around it and takes its electrons, giving 3 electrons on 2 shells (2 in shell K and 1 in shell L).
The lithium Bohr model built up in six seconds: the nucleus first, then each shell with its electrons, ending with 2 in shell K and 1 in shell L. Protons are red, neutrons yellow and electrons blue.

How to draw the lithium Bohr model

  1. Find the atomic number. Lithium has atomic number 3, so a neutral atom has 3 protons and 3 electrons.
  2. Draw the nucleus. Put a circle in the centre and write Li in it. The 3 protons sit there with the neutrons.
  3. Draw the shells. Sketch 2 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 and 1 in shell L.
  5. Check the total. 2 + 1 = 3, the atomic number, so every electron is accounted for.

Atomic data for the lithium Bohr model

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

Identity

Symbol
Li
Atomic number
3
Atomic mass
6.94 u
Family
Alkali Metals
Position
group 1, period 2
Block
s-block

Electron configuration

Full
1s2 2s1
Shorthand
[He] 2s1
Electrons per shell
2, 1
Outer-shell electrons
1 in shell L

Ionisation energies

I₁
520.2
I₂
7298.1
I₃
11815

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

Atomic radii

Calculated (pm)
167
Empirical (pm)
145
Covalent (pm)
133
Van der Waals (pm)
182

Electronegativity and electron affinity

Electronegativity (Pauling)
0.98
Electron affinity (kJ/mol)
59.633

Oxidation states

+1

Charges the element commonly takes in compounds.

Physical properties, abundance and history of lithium

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

Physical properties

Phase at room conditions
Solid
Appearance
Silvery-white
Melting point
180.5°C (453.65 K)
Boiling point
1329.85°C (1603 K)
Density
0.534 g/cm³
Thermal conductivity (W/m·K)
84.8
Specific heat (J/g·K)
3.582
Molar heat capacity (J/mol·K)
24.86
Heat of fusion (kJ/mol)
2.89
Heat of vaporisation (kJ/mol)
148

Abundance

Earth's crust (mg/kg)
20
Oceans (mg/L)
0.18

Discovery

Discovered by
Johan August Arfwedson
Year
1817

Common compounds

  • Lithium Chloride ClLi
  • Lithium Li
  • Lithium aluminum hydride AlH4Li
  • Lithium dihydrogen 5-sulphonatoisophthalate C8H5LiO7S
  • Lithium Bromide BrLi
  • Lithium fluoride FLi
  • Lithium perchlorate ClLiO4
  • Lithium (perfluorooctane)sulfonate C8F17LiO3S

Compounds listed in the PubChem database.

Main isotopes of lithium

Isotopes of lithium share the same 3 protons but differ in neutrons. Natural isotopes come first, then the longest-lived others.

Main isotopes of lithium: mass number, abundance, half-life and decay
Mass numberNatural abundanceHalf-lifeDecay
64.85 %stable–
795.15 %stable–
8–838.7 msβ⁻, β⁻α
9–178.2 msβ⁻, β⁻n
11–8.75 msβ⁻, β⁻n, 2n, 3n, β⁻α, β⁻d, β⁻t
13–3.3 zs2n

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

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