Element 1 · Hydrogen (H)
Hydrogen Bohr model: diagram and electrons per shell
The hydrogen Bohr model shows a hydrogen atom (H) as a small nucleus with its electrons circling it in 1 shell: 1 in shell K. This page has a rotating 3D hydrogen Bohr model, a flat diagram, a table of the electrons in each shell and the steps to draw it yourself.
Rotate the hydrogen Bohr model in 3D
Drag to orbit, scroll to zoom.
This is a Bohr model of hydrogen (H), a simplified picture of a single hydrogen atom. Its nucleus holds 1 proton, and a neutral hydrogen atom has 1 electron, arranged around it in 1 shell (1 in shell K).
Hydrogen Bohr model diagram
Hydrogen electrons per shell
A neutral hydrogen atom has 1 electron, one for each of its 1 proton. They fill the shells from the nucleus outwards: 1 in shell K.
| Shell | Shell number (n) | Electrons | Most it can hold (2n²) | Subshells |
|---|---|---|---|---|
| K | 1 | 1 | 2 | 1s1 |
How the hydrogen Bohr model builds up, shell by shell
Watch the hydrogen 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 (1 in shell K) as it forms.
How to draw the hydrogen Bohr model
- Find the atomic number. Hydrogen has atomic number 1, so a neutral atom has 1 proton and 1 electron.
- Draw the nucleus. Put a circle in the centre and write H in it. The 1 proton sit there with the neutrons.
- Draw the shells. Sketch 1 shell 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.
- Place the electrons. Fill from the inside out: 1 in shell K.
- Check the total. 1 = 1, the atomic number, so every electron is accounted for.
Atomic data for the hydrogen Bohr model
The numbers behind the hydrogen Bohr model, grouped by topic. Radii are in picometres (pm) and energies in kilojoules per mole (kJ/mol).
Identity
- Symbol
- H
- Atomic number
- 1
- Atomic mass
- 1.008 u
- Family
- Reactive Nonmetals
- Position
- group 1, period 1
- Block
- s-block
Electron configuration
- Full
- 1s1
- Shorthand
- 1s1
- Electrons per shell
- 1
- Outer-shell electrons
- 1 in shell K
Ionisation energies
- I₁
- 1312
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)
- 53
- Empirical (pm)
- 25
- Covalent (pm)
- 32
- Van der Waals (pm)
- 120
Electronegativity and electron affinity
- Electronegativity (Pauling)
- 2.2
- Electron affinity (kJ/mol)
- 72.769
Oxidation states
−1 +1
Charges the element commonly takes in compounds.
Physical properties, abundance and history of hydrogen
Bulk properties of hydrogen, how common it is, who discovered it and some of its compounds.
Physical properties
- Phase at room conditions
- Gas
- Appearance
- Colorless gas
- Melting point
- -259.16°C (13.99 K)
- Boiling point
- -252.88°C (20.271 K)
- Density
- 0.00008988 g/cm³
- Thermal conductivity (W/m·K)
- 0.181
- Specific heat (J/g·K)
- 14.304
- Molar heat capacity (J/mol·K)
- 28.836
- Heat of fusion (kJ/mol)
- 0.117
- Heat of vaporisation (kJ/mol)
- 0.904
Abundance
- Earth's crust (mg/kg)
- 1400
- Oceans (mg/L)
- 108000
Discovery
- Discovered by
- Henry Cavendish
- Year
- 1766
- Named by
- Antoine Lavoisier
Common compounds
- Pentachlorophenol C6HCl5O
- Hydrogen Cyanide CHN
- Sodium Bicarbonate CHNaO3
- Hydrochloric Acid ClH
- Nitric Acid HNO3
- Chloroform CHCl3
- Iodoform CHI3
- Trichloroethylene C2HCl3
Compounds listed in the PubChem database.
Main isotopes of hydrogen
Isotopes of hydrogen share the same 1 proton but differ in neutrons. Natural isotopes come first, then the longest-lived others.
| Mass number | Natural abundance | Half-life | Decay |
|---|---|---|---|
| 1 | 99.986 % | stable | – |
| 2 | 0.015 % | stable | – |
| 3 | – | 12.32 y | β⁻ |
| 4 | – | 139 ys | n |
| 6 | – | 294 ys | n, 3n |
| 7 | – | 652 ys | 2n |
α = alpha decay, β⁻ = beta-minus, β⁺ = beta-plus, EC = electron capture, SF = spontaneous fission, p / n = proton / neutron emission.
More about hydrogen
- Hydrogen on the periodic table – properties, isotopes, uses and the full hydrogen page.
- Reactive Nonmetals – all reactive nonmetal elements and their trends.
- Bohr model of every element – the Bohr model of all 118 elements.