periodic table

periodic table
/pear"ee od"ik, pear'-/, Chem.
a table illustrating the periodic system, in which the chemical elements, formerly arranged in the order of their atomic weights and now according to their atomic numbers, are shown in related groups.
[1890-95]

* * *

Organized array of all the chemical elements in approximately increasing order of their atomic weight.

They show a periodic recurrence of certain properties, first discovered in 1869 by Dmitry I. Mendeleyev. Those in the same column (group) of the table as usually arranged have similar properties. In the 20th century, when the structure of atoms was understood, the table was seen to precisely reflect increasing order of atomic number. Members of the same group in the table have the same number of electrons in the outermost shells of their atoms and form bonds of the same type, usually with the same valence; the noble gases, with full outer shells, generally do not form bonds. The periodic table has thus greatly deepened understanding of bonding and chemical behaviour. It also allowed the prediction of new elements, many of which were later discovered or synthesized.

* * *


Universalium. 2010.

Игры ⚽ Нужно решить контрольную?

Look at other dictionaries:

  • periodic table — n. an arrangement of the chemical elements according to their atomic numbers, to exhibit the periodic law: see the periodic table of elements in the Reference Supplement …   English World dictionary

  • periodic table — n the periodic table a list of ↑elements (=simple chemical substances) arranged according to their atomic structure …   Dictionary of contemporary English

  • periodic table — n an arrangement of chemical elements based on the periodic law * * * an ordering of all the known chemical elements in the form of a chart according to the periodic law, in which corresponding elements from the several periods form groups with… …   Medical dictionary

  • periodic table — ► NOUN ▪ a table of the chemical elements arranged in order of atomic number, usually in rows, with elements having similar atomic structure appearing in vertical columns …   English terms dictionary

  • Periodic table — This article is about the periodic table of the elements . For other uses, see The Periodic Table. The periodic table of the chemical elements (also known as the periodic table or periodic table of the elements) is a tabular display of the 118… …   Wikipedia

  • periodic table — noun (chemistry) a tabular arrangement of the chemical elements according to atomic number as based on the periodic law • Topics: ↑chemistry, ↑chemical science • Hypernyms: ↑table, ↑tabular array * * * noun [singular] chemistry : a list that …   Useful english dictionary

  • periodic table — N SING: the N In chemistry, the periodic table is a table showing the chemical elements arranged according to their atomic numbers …   English dictionary

  • periodic table, the — noun a list of chemical elements arranged according to the structure of their atoms …   Usage of the words and phrases in modern English

  • periodic table — table in which the chemical elements are arranged according their atomic numbers …   English contemporary dictionary

  • Periodic table (standard) — This is a typical display of the periodic table of the elements and contains the symbol and atomic number of each element. The periodic table of the chemical elements is a tabular method of displaying the chemical elements. Although precursors to …   Wikipedia

Share the article and excerpts

Direct link
Do a right-click on the link above
and select “Copy Link”