Barium is a metal in group IIA of the periodic table with atomic number 56, an atomic weight of 137.34, and a density of 3.5 Mg/m 3. Its melting point is 714 C, and it boils at 1640 C. The electronic ...

There are 118 elements in the periodic table, each with a unique symbol and atomic number. Symbol: A one or two-letter abbreviation used to represent the element. Atomic number: The number of ...

This uncertainty of just what Prometheus was responsible for is echoed in the uncertainty of who discovered the element promethium, number 61 in the periodic table. We know who named it ... Promethium ...