Teething refers to the process of new teeth rising or erupting through the gums. Teething can begin in infants as young as 2 months of age, even though the first tooth usually does not appear until about 6 months of age. Some dentists have noted a family pattern of early, average, or late teethers.
noble metal. 1. any of a number of metals, as gold, silver, mercury, or platinum, that resist oxidation when heated in air, and solution by inorganic acids. But now, at the first and yet final trial, she is proved and found to be of noble metal. There was a noble metal collarâabout thirty-two, the size would have been, on the usual scale.
Definition of Noble Gases. The periodic table is divided into 18 vertical columns referred to as groups or families. On the far right side of the periodic table, in group 18 is a unique group of elements known as the noble gases. The noble gases are a group of extremely nonreactive elements that all exist in the gas state. They are often considered to be inert. Inertness refers to an element's tendency to resist change and reactions.