- any of the oxides of barium, radium, strontium, calcium, and, sometimes, magnesium.
Origin of alkaline earth
First recorded in 1810–20
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018
Examples from the Web for alkaline earth
What properties have the alkaline-earth metals in common with the alkali metals?
Like the alkaline-earth metals, their carbonates and phosphates are insoluble in water.
The alkaline-earth family consists of the very abundant element calcium and the much rarer elements strontium and barium.
They are called the alkaline-earth metals because their properties are between those of the alkali metals and the earth metals.
Unlike both the alkali and alkaline-earth metals, their hydroxides are nearly insoluble in water.
- Also called: alkaline earth metal, alkaline earth element any of the divalent electropositive metals beryllium, magnesium, calcium, strontium, barium, and radium, belonging to group 2A of the periodic table
- an oxide of one of the alkaline earth metals
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012
- The oxides of calcium, strontium, radium, and barium, and sometimes magnesium.
The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.