Interessant. Danke!

Thanks for the answers, @schnurrito@discuss.tchncs.de! Because I access the communities from lemmy.ml, I was not sure if it easily will work with other instaces if I just use the link and subscribe. And I thought there might be a feature - that I miss - which automatically integrates the old and new contents.

And yes, I have seen the “locked” label. Still you could subscribe and read the content. That’s what’s confusing me. - If I don’t subscribe anymore, I will still find old topics by the search, right? So some question still remain, and it would be nice if people could answer what will happen to outdated communities/instances. - I guess they will stay online as long as their host servers are online? So in the future, we might have several communities with the same name, some “dead” some active?

Come to Europe one day! We have a selection of the finest vending machines in most gas stations toilets for - behold - not only condoms, but also tampons, little toys for her or him, etc. All for just a few bucks. And not sketchy at all.

My ELI5 answer: The periodic table is basically “finished”, there are no new additions. Meaning, the structure is is set and almost all elments found, including some (theoretical) higher-number elements that still have to be securely “discovered”. This final discovery nowadays happens only in specialised labs from time to time, because the higher-number elements are extremly unstable, only created artifically and existing for a few nanoseconds or femtoseconds. Some more details you can find on Wikipedia here: https://en.wikipedia.org/wiki/Actinide

Additionally, some people discuss different models/structures for organising the elements in general. But that is a different topic.