Noun

A noun (from Latin nōmen, literally meaning "name") is a word that functions as the name of some specific thing or set of things, such as living creatures, objects, places, actions, qualities, states of existence, or ideas.Linguistically, a noun is a member of a large, open part of speech whose members can occur as the main word in the subject of a clause, the object of a verb, or the object of a preposition.

Lexical categories (parts of speech) are defined in terms of the ways in which their members combine with other kinds of expressions. The syntactic rules for nouns differ from language to language. In English, nouns are those words which can occur with articles and attributive adjectives and can function as the head of a noun phrase.

History

Word classes (parts of speech) were described by Sanskrit grammarians from at least the 5th century BC. In Yāska's Nirukta, the noun (nāma) is one of the four main categories of words defined.

The Ancient Greek equivalent was ónoma (ὄνομα), referred to by Plato in the Cratylus dialog, and later listed as one of the eight parts of speech in The Art of Grammar, attributed to Dionysius Thrax (2nd century BC). The term used in Latin grammar was nōmen. All of these terms for "noun" were also words meaning "name". The English word noun is derived from the Latin term, through the Anglo-Norman noun.

Dental bonding

Adhesive dentistry is a branch of dentistry which deals with adhesion or bonding to the natural substance of teeth, enamel and dentin. It studies the nature and strength of adhesion to dental hard tissues, properties of adhesive materials, causes and mechanisms of failure of the bonds, clinical techniques for bonding and newer applications for bonding such as bonding to the soft tissue. There's also direct composite bonding which uses tooth-colored direct dental composites to repair various tooth damages such as cracks or gaps.

Dental bonding is a dental procedure in which a dentist applies a tooth-colored resin material (a durable plastic material) and cures it with visible, blue light. This ultimately "bonds" the material to the tooth and improves the overall appearance of teeth. Tooth bonding techniques have various clinical applications including operative dentistry and preventive dentistry as well as cosmetic and pediatric dentistry, prosthodontics, and orthodontics.

History

Chemical bond

A chemical bond is a lasting attraction between atoms that enables the formation of chemical compounds. The bond may result from the electrostatic force of attraction between atoms with opposite charges, or through the sharing of electrons as in the covalent bonds. The strength of chemical bonds varies considerably; there are "strong bonds" such as covalent or ionic bonds and "weak bonds" such as Dipole-dipole interaction, the London dispersion force and hydrogen bonding.

Since opposite charges attract via a simple electromagnetic force, the negatively charged electrons that are orbiting the nucleus and the positively charged protons in the nucleus attract each other. An electron positioned between two nuclei will be attracted to both of them, and the nuclei will be attracted toward electrons in this position. This attraction constitutes the chemical bond. Due to the matter wave nature of electrons and their smaller mass, they must occupy a much larger amount of volume compared with the nuclei, and this volume occupied by the electrons keeps the atomic nuclei relatively far apart, as compared with the size of the nuclei themselves. This phenomenon limits the distance between nuclei and atoms in a bond.