An element in the alkali group of metals with an atomic symbol K, atomic number 19, and atomic weight 39.10. It is the chief cation in the intracellular fluid of muscle and other cells. Potassium ion is a strong electrolyte that plays a significant role in the regulation of fluid volume and maintenance of the WATER-ELECTROLYTE BALANCE.
D002648
Child
A person 6 to 12 years of age. An individual 2 to 5 years old is CHILD, PRESCHOOL.
Children
D002675
Child, Preschool
A child between the ages of 2 and 5.
Children, Preschool,Preschool Child,Preschool Children
D006801
Humans
Members of the species Homo sapiens.
Homo sapiens,Man (Taxonomy),Human,Man, Modern,Modern Man
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Sodium
A member of the alkali group of metals. It has the atomic symbol Na, atomic number 11, and atomic weight 23.
Sodium Ion Level,Sodium-23,Ion Level, Sodium,Level, Sodium Ion,Sodium 23