- any of the group of bivalent metals including barium, radium, strontium, calcium, and, usually, magnesium, the hydroxides of which are alkalis but less soluble than those of the alkali metals.
Origin of alkaline-earth metal
First recorded in 1900–05
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018
- Any of a group of metallic elements including calcium, strontium, magnesium, barium, beryllium, and radium.
The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.
- Any of a group of metallic elements that includes beryllium, magnesium, calcium, strontium, barium, and radium. Because the alkaline-earth metals have two electrons in their outer shell, they react easily with other elements and are found in nature only in compounds. See Periodic Table.
The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.