So I’m teaching earth science, and I’ve been told that elements past carbon are only formed in the core of a massive star. The exam I’m preparing kids for, however, says that that there was a solar nebula that collapsed into the solar system, and was made of mostly hydrogen and helium. It also says that the gas giants were formed from the “light gases” of the nebula.
I’m guessing that the exam is fudging on the “mostly hydrogen and helium” thing, as this is for lower performing 9th graders. Was the sequence Big Bang, massive star, supernova, nebula, spinning disc, solar system?
Pretty much. The first stars had to condense from something.
And yes, our solar system is “mostly hydrogen and helium”- overwhelmingly so. But obviously there are heavier elements both in the rocky bodies and elsewhere.
The logic I think they hoping these 9th graders can grasp is something like this:
All of the heavier elements were formed in the crucible of a star.
Our solar system has rocky planets formed from heavier elements.
Our star has not gone supernova.
Therefore our solar system incorporates remnants from a previous supernova.
You should look at the Wikipedia page on stellar metallicity, especially the three populations of stars. Briefly, later stars and star systems have more elements beyond Hydrogen, Helium and a little Lithium. The earliest ones didn’t, but created those elements.
Pretty much all the elements heavier than helium in our solar system came from supernova explosions. A mid-sized star like the Sun will fuse carbon and oxygen, but those elements will remain trapped in the core rather than being dispersed off into space. When a really massive star goes supernova, the explosion itself generates the pressure needed to fuse heavier elements, with the added bonus of flinging them off into space to eventually go into the production of new solar systems like ours.