eli5:How is critical mass in plutonium-239 achieved?

Question

Eli5:How does this critical mass trigger a rapid and uncontrolled explosive chain reaction.?

In: Engineering

Answer 1

Reddit comments will only go so far to explain this topic. So I highly recommend the following video/ YouTube channel [here](https://youtu.be/LduH7613QXw?si=FG6DW_hcHf10FEG5)