how are elements made?
Atoms are made of 3 particles;
Electrons(low mass, negatively charged)
Neutrons(high mass, no charge)
Protons(high mass, positively charged).
We sort atoms by how many protons there is in the core. 1 proton means hydrogen, 2 means helium etc.
There’s some neutrons in there, but they don’t matter too much.
For each proton there will is an electron, and electrons are responsible for all the chemical reactions.
How are elements made? By stars. When the universe was created it was only hydrogen, helium and a tiny bit of lithium. Suns undergo a process called fusion, where atoms are fused together and create bigger ones. The sun gets a good portion of its energy from this process.
Some atoms are more likely to come from fusion. Helium, carbon, oxygen and iron are some of the big ones. Once we get up to iron something different happens. Iron is as far as you can go while still getting energy out of the fusion process. So when iron builds up in the core of a star it dies. Often that results in a supernova which is basically a massive explosion. Under a supernova there’s such much energy that iron is fused into the heavier elements like uranium.
Other than that, some atoms are not stable. This is called radioactivity. For instance sometimes atoms are hit by high energy particles and they change form. Sometimes this happens just automatically. This creates new atoms some with different amount of protons and thus different elements.
Lastly we have created a few elements in the lab. Basically by accelerating atoms to massive energies and having them hit each other.
[You’ve had the ELI5 answers but also wanna tack on this image that gives you direct info into which elements were created in which manner](https://imageio.forbes.com/blogs-images/startswithabang/files/2017/06/figshare_PT.jpg?format=jpg&width=960)
https://www.forbes.com/sites/startswithabang/2017/06/05/the-scientific-story-of-how-each-of-the-chemical-elements-was-made/ the article I got it from.
new elements in nature are only created in the cores of stars. During the normal parts of their lives the intense pressure and heat in the cores of stars causes nuclear fusion with light elements like hydrogen and helium, literally fusing the protons and neutrons together to form a heavier element. Depending on how large the star is this fusion process can keep going and be stable up until it starts trying to fuse together iron.
at that point or earlier most smaller stars either collapse and shed their outer layers to become a hot ball of matter known as a dwarf star, or in very large stars, go supernova and cause a massive explosion. its in these stellar “deaths” where the universe is given new elements. any elements the star had created through fusion up until now will be expelled when the star forms a dwarf or supernova, and during the final stage of the star’s life, the violent contractions and then explosions of both star types has enough pressure to create elements heavier than iron, up all the way to uranium. these are then blasted off into space to form a nebula that will in time birth new stars and planets.
All the elements up to Iron are made in stars as they go through their nuclear fusion process. All the heavier elements are made during super novas.
Free floating protons, neutrons, and electrons quickly grab each other to form hydrogen and helium.
Stars “burn” hydrogen and helium via fusion, forming bigger and bigger elements up as far as iron. Fusion stops at iron.
Then stars die or blow up. Either way, the resulting death rams a bunch of elementary particles together at ludicrous speed/pressure, fusing them into the elements higher than iron.
Some of those are unstable and later break down (fission) into smaller elements, which creates more.