PHYSICAL SCIENCE Viewpoint: Yes, atoms are real, and science has developed to the point that atoms can not only be seen, but can also be individually manipulated. Viewpoint: No, many pre-twentieth-century scientists, lacking any direct evidence of the...

smallest unit into which matter can be divided without the release of electrically charged particles. It also is the smallest unit of matter that has the characteristic properties of a chemical element. As such, the atom is the basic building block of...

Atoms and the subatomic particles that comprise them, are the elementary building blocks of material substances. Although the term atom, derived from the Greek word atomos, meaning indivisible, would seem inappropriate for an entity that, as science...

Atoms are the elementary building blocks of material substances. Although the term atom, derived from the Greek word atomos, meaning indivisible, would seem inappropriate for an entity that, as science has established, is divisible, the word atom still...

Atoms are the elementary building blocks of material substances. Although the term atom, derived from the Greek word atomos, meaning indivisible, would seem inappropriate for an entity that, as science has established, is divisible, the word atom still...

Atomic theory, first put in a quantitative conceptual framework by John Dalton, and quantum theory, which emerged in the 1920s as a result of the work of Werner Heisenberg, Erwin Schrödinger, and Max Planck, are the cornerstones of our present-day...

All matter, for practical purposes, is composed of atoms. They are discrete entities and indivisible under normal circumstances. This has a profound effect on all of chemistry in that any compound must be composed of a whole number of atoms. That is,...

Atoms are the smallest particles of matter that have distinct physical and chemical properties. Each different type of atom makes up an element which is characterized by an atomic weight and an atomic symbol. Since the atomic theory was first proposed...

In ancient philosophy, and until relatively recently, an atom was considered to be the ultimate unit of matter, and the building block of which more complex conceptual and physical constructs were built. This view has been extended to computer...

Just as a MOLECULE is the smallest quantity of a substance that retains the properties of that substance, so an atom is the smallest quantity of an ELEMENT possessing the properties of that element—that is, it is the smallest amount of an element...

Smallest unit into which matter can be divided and still retain the characteristic properties of an element. The word derives from the Greek atomos (“indivisible”), and the atom was believed to be indivisible until the early 20th century,...

The smallest unit of an element that still retains the chemical characteristics of that element. An atom is made up of protons and neutrons in a nucleus surrounded by electrons. A molecule of water (H2O) consists of two atoms of hydrogen and one atom...

The smallest portion of an ELEMENT that can take part in a chemical reaction with other...

n. See phonological...

In chemistry and physics, an atom (Greek á¼"τομος or átomos meaning "the smallest indivisible particle of matter, i.e. something that cannot be divided") is the smallest particle still characterizing a chemical element. An atom consists of a dense...