Mr Hassan’s Segrè Plot Lab

Drag to move · Scroll to zoom · Hover a nuclide for details

Student guide

What you’re seeing
Each square is one nuclide. The horizontal axis is Z (protons) and the vertical axis is N (neutrons). Moves right add protons; moves up add neutrons.

Decay is a step on the map
Hover an unstable nuclide to see an arrow to its daughter (when applicable). β⁻: Z + 1, N − 1 · β⁺ / EC: Z − 1, N + 1 · α: Z − 2, N − 2

Colour key (decay mode)

Stable

α decay

β⁻ decay

β⁺ / electron capture

Spontaneous fission

Other

Half-life colouring
In half-life mode, the colours represent the half-life on a logarithmic scale. Short half-lives look “hotter”; long half-lives look “colder”. Stable stays dark.

Mr Hassan’s Segrè Lab