What is antimatter?

Question

I've heard it a lot but don't quite understand what it actually is.

Answer 1

it is not really real i think, more of a theory. in regular matter electrons circle a nucleus that is comprised of protons and neutrons. in anti-matter the nucleus contains electrons and neutrons with the protons circling

Answer 2

In particle physics, antimatter extends the concept of the antiparticle to matter, wherein if a particle and its antiparticle come into contact with each other, the two annihilate —that is, they may both be converted into other particles with equal energy in accordance with Einstein's equation E = mc2. This gives rise to high-energy photons (gamma rays) or other particle–antiparticle pairs. The resulting particles are endowed with an amount of kinetic energy equal to the difference between the rest mass of the products of the annihilation and the rest mass of the original particle-antiparticle pair, which is often quite large.

Antimatter is not found naturally on Earth, except very briefly and in vanishingly small quantities (as the result of radioactive decay or cosmic rays). This is because antimatter which comes to exist on Earth outside the confines of a suitably equipped physics laboratory would inevitably come into contact with the ordinary matter that Earth is made of, and be annihilated. Antiparticles and some stable antimatter (such as antihydrogen) can be made in minuscule amounts, but not in enough quantity to do more than test a few of its theoretical properties.

There is considerable speculation both in science and science fiction as to why the observable universe is apparently almost entirely matter, whether other places are almost entirely antimatter instead, and what might be possible if antimatter could be harnessed, but at this time the apparent asymmetry of matter and antimatter in the visible universe is one of the great unsolved problems in physics. Possible processes by which it came about are explored in more detail under baryogenesis.

Answer 3

It is matter in the sense that it has mass and volume, but it is called "antimatter" because it is basically the "opposite" of the matter we are familiar with. More specifically, if matter and antimatter bump into each other, they destroy each other completely. Both the matter and an equal mass of the antimatter it contacted will utterly cease to exist, but in the process of anihilating one another, they will release tremendous energy (on the order of E=mc2... remember that old equation?)
At least in theory, you could have an entire galaxy made of antimatter that would look and behave like a normal-matter galaxy, right down to the stars and planets, even the molecules and organisms. All would be fine until a normal-matter object crossed its path...

Answer 4

In theory, any particle that exists in the Universe could have an anti-particle. For example, there exists an anti-electron (called a positron) which is just like an electron, except it carries a positive charge (the electron is negative). There are many ways to create positrons (even in nature). They have often been detected and even used in labs.

Anti-protons are a bit rarer (because they are more massive, they are more difficult to create in a lab). However, they do exist in the Universe. They are just like a proton except they have a negative charge (a proton is positive).

In normal matter, the atoms are made of protons (positive) and neutrons (no charge) in the nucleus; negative electrons orbit the positive nucleus.
In anti-matter, the nucleus contains anti-protons (negative) and anti-neutrons (no charge); positrons (positive electrons) orbit the nucleus.

When a particle meets its anti-particle, there is usually anhilation: both particles cancel each other and the mass of both particles becomes pure energy (E = m*c^2).

It is also possible for a concentration of pure energy to create a pair of particles. It takes more energy to create particles with lots of mass. That is why the very light electron-positron pair is easier to create than the more massive proton-antiproton pair.

Answer 5

Antimatter is a fundamental particle of regular matter with its electrical charge reversed.

Answer 6

Give an opposite sign to protons and electrons,this would be considered anti matter.
They could not exist together as they would annihilate each other!

Answer 7

opposite of matter is called antimatter.

Answer 8

its kinda like toejam,a stinky substance between your toes.

Answer 9

It is my mother-in-law

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