transition metal
noun
: any of various metallic elements (such as chromium, iron, and nickel) that have valence electrons in two shells instead of only one
called also transition element
Example Sentences
Recent Examples on the Web The first rare earth magnet to have been developed was based on the rare earth samarium and the transition metal cobalt. 
Mary Hui, Quartz, 14 May 2021 Rhenium is a rare transition metal, found at a concentration of about 0.001 parts per million in minerals around the world, particularly in Chile and the United States. Theresa Machemer, Smithsonian Magazine, 22 Jan. 2020 As a transition metal, rhenium can be creative with its bonds. Theresa Machemer, Smithsonian Magazine, 22 Jan. 2020 Most atoms can only form bonds with the electrons on their outermost shells, but transition metals can use the electrons from two outer layers. Theresa Machemer, Smithsonian Magazine, 22 Jan. 2020 Ruthenium is a transition metal, similar to platinum, that is used in electronics, solar cells, and some jewelry. Wired, 15 Aug. 2019
Mary Hui, Quartz, 14 May 2021 Rhenium is a rare transition metal, found at a concentration of about 0.001 parts per million in minerals around the world, particularly in Chile and the United States. Theresa Machemer, Smithsonian Magazine, 22 Jan. 2020 As a transition metal, rhenium can be creative with its bonds. Theresa Machemer, Smithsonian Magazine, 22 Jan. 2020 Most atoms can only form bonds with the electrons on their outermost shells, but transition metals can use the electrons from two outer layers. Theresa Machemer, Smithsonian Magazine, 22 Jan. 2020 Ruthenium is a transition metal, similar to platinum, that is used in electronics, solar cells, and some jewelry. Wired, 15 Aug. 2019 Word History
Etymology
from their being transitional between the more highly and the less highly electropositive elements
First Known Use
1929, in the meaning defined above