A table in which the chemical elements are arranged in order of increasing atomic number. Elements with similar properties are arranged in the same column (called a group), and elements with the same number of electron shells are arranged in the same row (called a period).
a very light colorless element that is one of the six inert gasses; the most difficult gas to liquefy; occurs in economically extractable amounts in certain natural gases (as those found in Texas and Kansas)
Find another word for helium. In this page you can discover 3 synonyms, antonyms, idiomatic expressions, and related words for helium, like: periodic-table, he and atomic number 2.