Calcium is a silvery, gray metal found in rocks, bones, leaves and shells. Humans have been using calcium, in the form of limestone and gypsum, for thousands of years. Calcium carbonate is a common combination of calcium, found in marble, limestone and gypsum.
Location
Calcium is located in the second column from the left in the fourth row of the periodic table, classifying it as an alkaline earth metal.
Chemical Symbol
The element calcium is represented with a capital "C" and a lowercase "a" on the periodic table. The chemical symbol is centered on the information square designated for calcium.
Atomic Number
Calcium has 20 protons in its nucleus, called the atomic number. The periodic table lists the atomic number, which is 20, above the chemical symbol.
Atomic Weight
Calcium has an atomic weight of 40.08, located below the chemical symbol on the periodic table. Atomic weight is the average of all the isotopes of calcium in the natural world, of which there are six.
Significance
Calcium is the fifth most abundant element on earth, consisting of nearly three percent of the Earth's crust. In nature, calcium is found combined with other elements like carbon (calcium carbonate), nitrogen (calcium nitrate) and chlorine (calcium chloride).
Tags: periodic table, chemical symbol, atomic number, calcium found, limestone gypsum
