Actinium, Chemical Element
Actinium is the third element in Row 7 of the periodic table, a chart that shows how the chemical elements are related to each other. Some chemists place it in Group 3 (IIIB), with scandium and yttrium.
Aluminum, Chemical Element
Aluminum is found in Row 2, Group 13 of the periodic table. The periodic table is a chart that shows how the chemical elements are related to each other.
Americium, Chemical Element
Americium is called an actinide or transuranium element. It occurs in Row 7 of the periodic table, a chart that shows how the chemical elements are related to each other.
Antimony, Chemical Element
Antimony compounds have been used by humans for centuries. Women of ancient Egypt used stibic stone, antimony sulfide, (Sb2S3), to darken their eyes.
Argon, Chemical Element
Argon is a noble gas. The noble gases are the six elements in Group 18 (VIIIA) of the periodic table.
Arsenic, Chemical Element
Arsenic compounds have been known since at least the days of Ancient Greece and Rome (thousands of years ago). They were used by physicians and poisoners.
Astatine, Chemical Element
Astatine is a member of the halogen family, elements in Group 17 (VIIA) of the periodic table. It is one of the rarest elements in the universe.
Barium, Chemical Element
Barium was first isolated in 1808 by English chemist Sir Humphry Davy (1778-1829). In 1807 and 1808, Davy also discovered five other new elements: sodium, potassium, strontium, calcium, and magnesium.
Berkelium, Chemical Element
In the period between 1940 and 1961, eleven transuranium elements were discovered by researchers from the University of California at Berkeley (UCB). The term transuranium element refers to elements beyond uranium (atomic numbers greater than 92) in the periodic table.
Beryllium, Chemical Element
Beryllium is the lightest member of the alkaline earth metals family. These metals make up Group 2 (IIA) of the periodic table.
Bismuth, Chemical Element
Early chemists had difficulty separating similar elements from each other. Elements with similar properties can only be told apart with tests not available before the eighteenth century.
Boron, Chemical Element
Boron is the first element in Group 13 (IIIA) of the periodic table. The periodic table is a chart that shows how the chemical elements are related to each other.
Bromine, Chemical Element
Bromine is a member of the halogen family. Halogens are the elements that make up Group 17 (VIIA) of the periodic table.
Cadmium, Chemical Element
Cadmium is a transition metal. The transition metals are the elements found in Rows 4 through 7 between Groups 2 and 13 in the periodic table, a chart that shows how elements are related.
Calcium, Chemical Element
Calcium is an alkaline earth metal. The alkaline earth metals make up Group 2 (IIA) of the periodic table, a chart that shows how the elements are related.
Californium, Chemical Element
Californium is a transuranium element, or "beyond uranium" on the periodic table. The periodic table is a chart that shows how chemical elements are related to each other.
Carbon, Chemical Element
Carbon is an extraordinary element. It occurs in more different forms than any other element in the periodic table.
Cerium, Chemical Element
Cerium is the most abundant of the rare earth metals. Rare earth metals are the elements in Row 6 of the periodic table.
Cesium, Chemical Element
Cesium is a member of the alkali family, which consists of elements in Group 1 (IA) of the periodic table. The periodic table is a chart that shows how chemical elements are related to each other.
Chlorine, Chemical Element
Chlorine ranks among the top 10 chemicals produced in the United States. In 1992, about 10.5 billion kilograms (23 billion pounds) of the element were produced in the United States.
Chromium, Chemical Element
Chromium is found in the center of the periodic table, a chart that shows how chemical elements are related to each other. Elements in Groups 3 through 12 are known as the transition metals.
Cobalt, Chemical Element
Humans have been using compounds of cobalt since at least 1400 B.C. The compounds were used to color glass and glazes blue.