what is an atom?

Answer 1

In chemistry and physics, an atom (Greek ἄτομος or átomos meaning "indivisible") is the smallest particle of a chemical element that retains its chemical properties. (átomos is usually translated as "indivisible." Until the advent of quantum mechanics, dividing a material object was invariably equated with cutting it.) Whereas the word atom originally denoted a particle that cannot be cut into smaller particles, the atoms of modern parlance are composed of subatomic particles:

electrons, which have a negative charge, a size which is so small as to be currently unmeasurable, and which are the least heavy (i.e., massive) of the three;
protons, which have a positive charge, and are about 1836 times more massive than electrons; and
neutrons, which have no charge, and are about 1838 times more massive than electrons.
Protons and neutrons make up a dense, massive atomic nucleus, and are collectively called nucleons. The electrons form the much larger electron cloud surrounding the nucleus.

Atoms can differ in the number of each of the subatomic particles they contain. Atoms of the same element have the same number of protons (called the atomic number). Within a single element, the number of neutrons may vary, determining the isotope of that element. The number of electrons associated with an atom is most easily changed, due to the lower energy of binding of electrons. The number of protons (and neutrons) in the atomic nucleus may also change, via nuclear fusion, nuclear fission or radioactive decay, in which case the atom is no longer the same element it was.

Atoms are electrically neutral if they have an equal number of protons and electrons. Atoms which have either a deficit or a surplus of electrons are called ions. Electrons that are furthest from the nucleus may be transferred to other nearby atoms or shared between atoms. By this mechanism atoms are able to bond into molecules and other types of chemical compounds like ionic and covalent network crystals.

Atoms are the fundamental building blocks of chemistry, and are conserved in chemical reactions.

Answer 2

An ATOM is "The smallest part of an Element which retains the properties of that Element".

To try to explain the size of an Atom, look at the full-stop at the end of this sentence.←

IT IS MADE UP OF ABOUT 2 MILLION ATOMS.

An Atom consists of Protons (+) and Neutrons (Neutral) in its Nucleus (Centre) and one or more Electrons (-), orbiting the nucleus.

The smallest atom is that of Hydrogen having 1 proton and 1 electron.

The largest (as far as known) is Lawrencium (Lw) (man-made), which has 103 Protons, 103 Electrons and something like 154 Neutrons (Lw Atomic mass(weight) = 257).
Electron mass is considered negligible at 1/1840th of that of a Proton.

Answer 3

Atoms are the smallest part of any material that cannot be broken up by chemical means. Each atom has a center (the nucleus) which contains protons and neutrons. Electrons orbit around the nucleus. In an uncharged atom the number of electrons orbiting the nucleus equals the number of protons in the nucleus. The atom is primarily empty space. ...

Answer 4

An atom is a particle of matter, that cannot be subdivided chemically. It can be subdivided physically into three components.
1st component is a proton - it has a positive (+) charge.
2nd component is a neutron - it has a zero charge.
3rd component is an electron - it has a negative (-) charge.
Mass of proton is 1
Mass of neutron is 1
Mass of electron is zero (0)
These masses are arbiitrarily chosen values because they are in a this simple ratio.
These three components are arranged in the following manner:-

The Proton and Neutron form the nucleus of the atom - its core.
The Electron surround the nucleus in numerous energy shells. - the further away from the nucleus the electron, the more energy it has, so it will require less energy to remove it from the atom to form an ion.
An atom must have the same number of protons and electrons so that IT is charge neutral.
It my have different numbers of neutrons and so is an isotope.
Different elements have different numbers of protons in the nucleus.
The simplest atom is the hydrogen atom.
It consists of one proton and one electron.
Hydrogen has and isotope (Deuterium) consisting of one proton, one electron and one neutron.

Another element is Carbon
It consists of 6 protons and 6 neutrons in its nucleus and 6 electrons. It is described as CARBON - 12
An isotope of carbon is CARBON - 13
This isotope consists of 6 protons, 7 Neutrons and 6 electrons.

Answer 5

An atom is the smallest unit of matter. It is made up of a nucleus containing positively charged protons and neutral neutrons, and the orbital /shells containing electrons, apart from about 97 other sub atomic particles like leptons,mesons etc, which are not really reqd. to know at school level.

Answer 6

Atoms are the basic building blocks of ordinary matter. Atoms can join together to form molecules, which in turn form most of the objects around you.

Answer 7

atoms are the tiny particles that make up the different elements. THey are made up of varying numbers of protons, neutrons and electrons, me thinks. When elements mix and react with each other, they make compunds.

Answer 8

It is the smallest particle that defines an element. As per the Periodic Table of Elements.

Answer 9

It is the structural and functional unit of all the things in this Universe. It is made up of nuetrons, protons and electrons which are null, positively and negatively charged respectively

Answer 10

Its a fast kit car with a Honda Civic Type-R engine in it

Also its a particle which makes up something i think.