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 ...

The handy visual reference guide organizes known chemical elements in rows and columns, arranged by their atomic number. One never knows when one will need the properties of Rutherfordium in a hurry.

Hydrogen is a gas in group IA of the periodic table with atomic number 1, an atomic weight of 1.008, and a density of 0.071. Hydrogen forms an hcp solid at low temperatures, melting at - 259.2 C and ...

The periodic table of chemical elements, often called the periodic table, organizes all discovered chemical elements in rows (called periods) and columns (called groups) according to increasing atomic ...

The periodic table The periodic table is a chart of all the elements arranged in increasing atomic number. Group 1 alkali metals The Group 1 elements, also known as the alkali metals, all react ...

For example, the atomic number of sodium is 11. Every sodium atom has 11 protons and 11 electrons. It has 11 positive charges and 11 negative charges. The mass number of an atom is its total ...