Is embedding the radioactive decay simulator free?

Yes. It is free to embed on any site, with no account, no API key and no usage limits. The whole simulation runs in your visitor’s own browser, so there is no server cost — we only ask that you keep the small "Radioactive Decay Simulator by LK Forge" credit line that comes with the embed code.

What can visitors do with the embedded simulator?

They can set the half-life, the number of starting nuclei and the simulation speed, then watch a grid of nuclei wink out at random one by one. A live panel shows how many remain, how many have decayed, the elapsed time in seconds and in half-lives, and the fraction remaining — while a decay curve traces the survivor count against the ideal exponential with gridlines at each half-life.

Does the embed teach half-life and exponential decay?

Yes, by demonstration. Because each nucleus is given the same fixed chance to decay each step, the survivor count follows N = N0 times 2 to the power minus t over the half-life, and the curve lands near N0/2, N0/4 and N0/8 at one, two and three half-lives. Students see the smooth exponential emerge from genuinely random individual decays, and how a larger sample hugs the ideal curve more closely.

What iframe height should I use, especially on mobile?

The snippet ships with height="1000", which is tall enough that the grid of nuclei, the controls, the readouts and the decay curve all fit without clipping even on a narrow phone where everything stacks into a single column. On a wider page the widget simply centres within its max-width of 560px. If you want it shorter you can lower the height, but 1000 is the safe default across screen sizes.

Where can I embed it — WordPress, Wix, Squarespace, Notion?

Anywhere you can add HTML, because it is a standard iframe. In WordPress use a Custom HTML block; in Squarespace a Code/Embed block; in Wix an Embed HTML element; in Ghost an HTML card; in Notion paste the /embed/radioactive-decay/ URL as an embed. On a plain HTML page or an intranet, paste the snippet straight into the markup.

Does the embedded simulator track visitors or set cookies?

No. Everything runs locally in the visitor’s browser — nothing is uploaded. The embed sets no tracking cookies and sends no analytics, so it is safe to place on a privacy-sensitive site, an intranet, or a page for students.

Widgets

How to Add a Radioactive Decay Simulator to Your Website

LK Forge · 4 min read · Updated September 2026

You can add a full radioactive decay simulator to any website, blog, or classroom page with a single line of code — free, with no sign-up, no plugin, and no script to install. Visitors watch a population of nuclei decay at random and see the exponential half-life curve appear. This guide covers the fastest way to embed the Radioactive Decay Simulator, what it teaches, and where it works.

The quickest way: paste one embed snippet

An embed is just an <iframe> that loads the simulator from lkforge.com, plus a small credit line. Copy this into your page’s HTML where you want the widget to appear:

<iframe src="https://lkforge.com/embed/radioactive-decay/"
        width="100%" height="1000" loading="lazy"
        style="border:0;max-width:560px"
        title="Radioactive Decay Simulator by LK Forge"></iframe>
<p><a href="https://lkforge.com/tools/physics/radioactive-decay/">Radioactive Decay Simulator</a>
   by <a href="https://lkforge.com/">LK Forge</a></p>

The <iframe> is the live simulator; the <p> underneath is a plain credit link. Keep that line — the visible link is what keeps the widget free to embed. You can also copy this exact code straight from the LK Forge widget gallery.

What the widget shows

The simulator opens with the nuclei already decaying, so a visitor sees the dots thinning out immediately and can then take control:

Half-life: set how quickly the sample decays and watch the curve steepen or flatten.
Starting nuclei: choose the sample size — bigger samples hug the ideal curve more tightly.
Speed: run the decay faster or slower.
Live readouts and curve: the count remaining, decayed, elapsed time in half-lives, and a decay curve with the ideal exponential overlaid and half-life gridlines.

Pick the right height

The snippet uses height="1000", which fits the nuclei grid, the controls, the readouts and the decay curve without clipping even on a narrow phone, where they stack into one column. On a wider page the widget centres within its max-width:560px. That single height works across screen sizes, so there is nothing to tweak for mobile.

Where it works

Because it is a standard iframe, the embed works anywhere you can add HTML:

WordPress: add a Custom HTML block and paste the snippet.
Squarespace: use a Code / Embed block.
Wix: add an Embed HTML / iframe element.
Ghost: insert an HTML card.
Notion: paste the /embed/radioactive-decay/ URL and choose "Create embed".
Plain HTML, an intranet, or a lesson page: paste the snippet straight into the markup.

That’s the whole job. Copy the embed code from the widget gallery and paste it wherever a physics or chemistry lesson on radioactivity, half-life or exponential decay needs a sample students can actually watch decay.

Grab the embed code from the LK Forge widget gallery — free, no sign-up.

Open the Radioactive Decay Simulator

Frequently asked questions

Is embedding the radioactive decay simulator free?: Yes. It is free to embed on any site, with no account, no API key and no usage limits. The whole simulation runs in your visitor’s own browser, so there is no server cost — we only ask that you keep the small "Radioactive Decay Simulator by LK Forge" credit line that comes with the embed code.
What can visitors do with the embedded simulator?: They can set the half-life, the number of starting nuclei and the simulation speed, then watch a grid of nuclei wink out at random one by one. A live panel shows how many remain, how many have decayed, the elapsed time in seconds and in half-lives, and the fraction remaining — while a decay curve traces the survivor count against the ideal exponential with gridlines at each half-life.
Does the embed teach half-life and exponential decay?: Yes, by demonstration. Because each nucleus is given the same fixed chance to decay each step, the survivor count follows N = N0 times 2 to the power minus t over the half-life, and the curve lands near N0/2, N0/4 and N0/8 at one, two and three half-lives. Students see the smooth exponential emerge from genuinely random individual decays, and how a larger sample hugs the ideal curve more closely.
What iframe height should I use, especially on mobile?: The snippet ships with height="1000", which is tall enough that the grid of nuclei, the controls, the readouts and the decay curve all fit without clipping even on a narrow phone where everything stacks into a single column. On a wider page the widget simply centres within its max-width of 560px. If you want it shorter you can lower the height, but 1000 is the safe default across screen sizes.
Where can I embed it — WordPress, Wix, Squarespace, Notion?: Anywhere you can add HTML, because it is a standard iframe. In WordPress use a Custom HTML block; in Squarespace a Code/Embed block; in Wix an Embed HTML element; in Ghost an HTML card; in Notion paste the /embed/radioactive-decay/ URL as an embed. On a plain HTML page or an intranet, paste the snippet straight into the markup.
Does the embedded simulator track visitors or set cookies?: No. Everything runs locally in the visitor’s browser — nothing is uploaded. The embed sets no tracking cookies and sends no analytics, so it is safe to place on a privacy-sensitive site, an intranet, or a page for students.