The definition of an atom is the smallest component of an element, characterized by a sharing of the chemical properties of the element and a nucleus with neutrons, protons and electrons.
Structure of an Atom
- An atom includes a nucleus, and then a series of orbital circles that surround this nucleus similar to the solar system structure.
- The protons and the neutrons reside in the nucleus.
- The electrons are in the orbitals.
- The amount of protons in the nucleus of an atom determines its atomic number.
Hydrogen and helium are examples of elements that have an atom.
A model of an atom.
atom definition by Webster's New World
- Obsolete any of the indivisible particles postulated by philosophers as the basic component of all matter
- a tiny particle of anything; jot
- Chem., Physics any of the smallest particles of an element that combine with similar particles of other elements to produce compounds: atoms combine to form molecules, and consist of a complex arrangement of electrons revolving about a positively charged nucleus containing (except for hydrogen) protons and neutrons and other particles
Origin: Middle English attome ; from Old French atome ; from Classical Latin atomus ; from Classical Greek atomos, uncut, indivisible, atom ; from a-, not plush tomos ; from temnein, to cut: see -tomy
atom definition by American Heritage Dictionary
noun
- a. A part or particle considered to be an irreducible constituent of a specified system.b. The irreducible, indestructible material unit postulated by ancient atomism.
- An extremely small part, quantity, or amount.
- Physics & Chemistry a. A unit of matter, the smallest unit of an element, having all the characteristics of that element and consisting of a dense, central, positively charged nucleus surrounded by a system of electrons. The entire structure has an approximate diameter of 10-8 centimeter and characteristically remains undivided in chemical reactions except for limited removal, transfer, or exchange of certain electrons.b. This unit regarded as a source of nuclear energy. See Table at subatomic particle.
Origin: Middle English attome, from Latin atomus, from Greek atomos, indivisible, atom : a-, not; see a-1 + tomos, cutting (from temnein, to cut; see tem- in Indo-European roots).
atom
carbon atom
atom - Computer Definition
(1) (Atom) Intel x86 chips. See Atom chips.
(2) (Atom) A Web feed. See Atom syndication format.
(3) A single element. See atomic.
(4) A fundamental building block of matter. Atoms are microscopic solar systems that are made up of particles and mostly space. Within that space, electrons create an outer shell by circling a nucleus containing protons and neutrons of similar mass. Neutrons have no electrical charge, but protons have a positive charge. Since there are the same number of electrons as there are protons, and since electrons have a negative charge, the atom has a net charge of zero. See electron. Since the days of ancient Greece, the atom was considered "the" smallest element of matter and indivisible, which is what "atomic" means. However, in the 1960s, we discovered that the nucleus was made up of more particles, which were named quarks and leptons. Perhaps some day, we will find those particles made up of even more particles in our never ending quest to discover what we are really made of.
Does It Really Matter?
World-renowned scientist and Nobel Prize winner Max Planck once made a remarkable comment about the structure of matter that has been widely quoted ever since... "As a man who has devoted his whole life to the most clear-headed science, to the study of matter, I can tell you as the result of my research about atoms this much: THERE IS NO MATTER AS SUCH! All matter originates and exists only by virtue of a force which brings the particles of an atom to vibration and holds this most minute solar system of the atom together. We must assume behind this force the existence of a conscious and intelligent mind. This mind is the matrix of all matter."atom - Cultural Definition
atom - Medical Definition
noun
- A unit of matter, the smallest unit of an element, having all the characteristics of that element and consisting of a dense, central, positively charged nucleus surrounded by a system of electrons. The entire structure has an approximate diameter of 10-8 centimeter and characteristically remains undivided in chemical reactions except for limited removal, transfer, or exchange of certain electrons.
- This unit regarded as a source of nuclear energy.
- A part or particle considered to be an irreducible constituent of a specified system.
- The irreducible, indestructible material unit postulated by ancient atomism.
- An extremely small part, quantity, or amount.
Related Forms:
- atomic adjective
atom - Phrases/Idioms
the atom
atom - Science Definition
