Do most elements generally exist in a planet during early formation, or is it a small subset? I'm interested in whether there are a small subset of elements that are by far the most common in a planet's early stages of formation and a wider range are formed slowly over time through chemical reaction, or if a very wide range of the periodic table can be initially found from the start.
Obviously every planet it unique, but I'm asking about whether there's a common scenario / elemental ratio present in the hot cataclysmic early stages of a planet's formation, or rather it's pretty much diverse from the start. Do most elements generally exist in a planet during early formation, or is it a small subset?
Elements are not formed through chemical reactions or in planets (except through nuclear decay) . They are formed in stars through nuclear reactions.
Your heavier elements can't even be formed in your typical star. It takes a supernova.
So pretty much everything the planet is made of is there from the start.