That is one of the unsolved problems in cosmology. There seems to be a slight difference between matter and antimatter, that is, the symmetry between matter and antimatter is not perfect. But the details of baryogenesis are not known yet.
That is not currently known. There is a slight assymetry between matter and antimatter, but so far, it seems that this assymetry is not enough to explain why there is only matter, and hardly any antimatter, in the Universe. Without such an assymetry, there wouldn't be either matter or antimatter in the Universe - just radiation. For more information about what is known, and what isn't, check the Wikipedia article on "Baryon asymmetry".
Matter, or antimatter.
When antimatter comes into contact with matter, they annihilate each other.
Initially the 9g of remaining matter would survive. Each particle of antimatter can only annihilate with one other particle of antimatter. At this point the 1g of antimatter would cause an explosion equivalent to that of 200000 pounds of TNT. Causing both groups of matter and antimatter to be obliterated.
No, Antimatter while annihilate our matter, meaning that it will completely convert our matter to light and heat, however antimatter is highly theoretical, and the LHC probably will not create any.
1. Why is there more matter than antimatter in the Universe? Or: Why is there matter at all? (If there were the same amount of matter and antimatter, and it came into contact, it would quickly get destroyed. 2. If antimatter is so abundant, how come we've never come in contact with it or have been able to observe it?
You are giving the definition for the Big Bang Theory.
In the early universe, matter and antimatter were created in equal amounts. As the universe cooled and expanded, there was a slight imbalance in favor of matter over antimatter. This allowed the matter to survive and form the structures we see today, while most of the antimatter annihilated with matter, resulting in the predominance of matter in the universe.
antimatter and dark matter
A thing that not matter is antimatter. It has been created by man.
Absolutely not - Antimatter is a hypothetical form of matter that is as yet unsubstantiated. Answer It's possible but not probable. And antimatter is not hypothetical
PCH: Antimatter