Describe the structure of an atom?

Answer 1

An atom is the most basic unit of a chemical element. It comprises two main parts. The first part is a very dense and very small core called a nucleus. Most of the mass of the atom is concentrated in the nucleus, and it is made up from protons and neutrons. The second part is a "cloud" of electrons, that move around the nucleus in various positions called "energy levels". The nucleus is made up of protons and neutrons. Protons and neutrons have roughly the same mass, although the neutron is slightly heavier, and they have a mass of about 1,840 times that of an electron. Protons and neutrons are collectively known as nucleons. Nuclei that contain the same number of nucleons are called isobars. The number of protons in the nucleus of the atom is what makes the chemical element unique. All atoms of Carbon, for example, contain six protons. Not all carbon atoms contain the same number of neutrons: the most common carbon atom ("Carbon-12") contains six protons and six neutrons, whereas another type ("Carbon-14") contains six protons and eight neutrons. Carbon-12 and Carbon-14 are known as isotopes of carbon. Neutrons, as the name suggests, are electrically neutral particles. They are needed in the nucleus in the right number, to make it stable. When the number of neutrons is fixed and the number of protons is allowed to change, the result is known as isotones of the nucleus. For example, a nucleus containing one proton and two neutrons ("Hydrogen-3", or Tritium) and a nucleus containing two protons and two neutrons ("Helium-4"), are known as isotones.

The neutron was discovered in 1932 by James Chadwick. It is stable when in the nucleus of an atom, but alone it decays into a proton, and electron and another particle called an antineutrino. Each proton has a positive electrical charge of one unit, so for an atom to be electrically neutral it must have the same number of electrons. These electrons do not "fall" into the nucleus, attracted by the protons. The reason is explained by Quantum Theory, which states that they may only exist at certain, specific energy "levels", or "shells". The first shell can hold two electrons, the second can hold eight electrons, and the nth can hold 2 x n-squared electrons. As a general rule, each shell is more stable when it is full. Shells that are more than half full tend to want extra electrons, and shells that are less than half-full tend to want to lose electrons. The number of electrons that an atom wants to gain or lose is called the "valency". Protons are what make a chemical element what it is. They reside in the nucleus along with neutrons, which are slightly heavier but which have no electrical charge. Electrons are much lighter, and revolve around the nucleus in "shells" of given energy levels. Each shell is more stable when it is "complete", and the degree of completeness gives every element its chemical bonding properties.

Answer 2

The atom is aunique particle that consist of the protons(positove)and the electrons(negative)and it is in any object.What ever object that does not take up a an atom is consist of empty space.

Answer 3

THE EXPLANATION OF AN ATOMprotons are what make a chemicalelement. They reside in the nucleus alongwith neutron,which are slightly heavier but which have no electrical charge. Electrons are much lighter,and revolve around the nucleus in "shells" of given energy levels.Each shells is more stable when it is "complete",and the degree of completeness gives every elementits chemical bonding properties.

Answer 4

An atom has three basic things:

# Nucleus # Open space # Electron cloud/orbitals

In the nucleus, protons (positively charged particle made up of 2 up quarks and one down quark) and neutrons (neutrally-charged particle made up of 2 down quarks and one up quark) make the nucleus positively charged. It is in the center of the atom.

Surrounding the nucleus is a large (relative term) amount of empty space.

In that empty space is known as the electron cloud and electron orbitals. In these orbitals are all the electrons in the atom, arranged in an order following different laws and principles of chemistry.

This is a pretty basic description.

Answer 5

All atoms consist of two regions. The nucleus is a very small region located near the center of an atom. In every atom the nucleus contains at least one positively charged particle called a proton and usually one or more neutral particles called neutrons. Surrounding the nucleus is a region occupied by negatively charged particles called electrons. This region is very large compared with the size of the nucleus. Protons, neutrons, and electrons are often referred to as subatomic particles.

Answer 6

an atom is the smallest indivisible paticle which can take place in a chemical reaction.

Answer 7

An atom consists of protons, electrons, and neutrons.

Answer 8

An atom consists of three sub atomic particles. They are protons, neutrons, and electrons. These are found in the nucleus of the atom.

Answer 9

An atom consists of a nucleus, which contains protons and neutrons, surrounded by an electron cloud containing the electrons.