How did matter form?

Answer 1

Matter did not form from nothing, as this violates the law of conservation of mass. Rather, energy was converted into subatomic particles shortly after the Big Bang. However, due to the extremely hot and dense state of the Universe at the time, it would take thousands of years for true matter to finally assemble.

Below is the time line that leads up to the formation of matter:

In the very beginning, a singularity of extreme heat and density goes through an extremely fast inflation. Space and time suddenly originates, and the Universe expands to billions of times its original size in 10-43 seconds. This initial expansion is commonly known as the "Big Bang"

About 10-32 seconds after the Big Bang, energy is converted into a variety of subatomic particles, and the Universe is a seething hot soup of quarks and electrons

Nearly a second after the Big Bang, a rapidly cooling Universe permits quarks to clump together and form protons and neutrons. However, it is still too hot for atoms to assemble.

A few minutes after the Big Bang, the Universe continues to cool and expand, and protons and neutrons combine to form the first hydrogen nuclei. Photons interact with charged protons and electrons, preventing light from shining. The Universe is dark and opaque.

Thousands of years after the Big Bang, the Universe cools down enough for electrons to combine with protons and neutrons to form the first atoms. This is when true matter forms. Photons are also released and the Universe becomes transparent and filled with light.

The first element is hydrogen. Clouds of hydrogen gas condense to form stars, and from there, all the other elements are produced.

Answer 2

Stardust.

Hydrogen, some helium, and less lithium were created during the big bang. Everything else was made inside the cores of stars (elements on the Periodic Table up to iron) or supernova explosions (elements heavier than iron.)