The sun formed 4.5 billion years ago and was made up of 98% Hydrogen +Helium and 2% the rest of the periodic table including Silicon. So, the Silicon we see on earth was here from the beginning just as the sun and planets formed 4.5 billion years ago.

Where does all the silicon on Earth come from? Well, I am sure you have heard of the term “atom”. Atoms are the building blocks of all the material in the universe and they are made of little particles called protons, neutrons and electrons. There are many different types of atoms and the type is determined by the number of protons. For example hydrogen has one proton, helium has two, and Lithium has three and so on. Silicon is also a type of atom and has 14 protons.

When the universe was created in the big bang, first there were only single protons flying around. So there was only one type of atom (hydrogen). New types of atoms can form when protons get really hot, come together and join. This is called nuclear fusion and creates a lot of energy. In fact the sun shines because of hydrogen joining together to make helium. When more and more protons join together they form more and more different types of atoms. Silicon with 14 protons is the 8th most abundant type of atom in the universe so that means that there is quite a lot of it.

Now we know how the different types of atoms form but how did so much silicon from the universe ended up on planet Earth? Well, before the sun and the planets existed there was just a giant cloud of different types of atoms that formed a dust. The dust slowly came together and started rotating faster and faster. More and more dust particles became attracted to each other, collided and formed larger and larger bodies. That way the sun and the planets formed. The sun was in the center and the planets were rotating around it. But the sun was very, very hot and many types of atoms could not survive in that heat and were driven far away from the sun. Only material that was mostly made of iron, silicon and oxygen stayed close to the sun and many of the other atoms were pushed further away. Therefore, the planets that are close to the sun (Mercury, Venus, Earth, Mars) are made of mostly iron, silicon and oxygen and just small numbers of the other types of atoms.

Now the last question that remains is where did all the iron go? There is a little bit of iron on the Earth surface but is there so much more silicon? Well, much of the iron, because it is so much heavier than silicon, sank to the core of the Earth, whereas the silicon stayed on the outside. For that reason the rocks at the surface of the Earth today are made out of a lot of silicon.

Silicon is an element and a major component of most rocks. It would have arrived on Earth in the form of dust and meteorites in the early solar system that made the rocky planets.