The covalent radius (a measure of how large individual atoms are) shows different trends if you are moving across a period or down a group. A comparison of the relative covalent radii of atoms is ...

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 ...

Students learn to describe the pattern in atomic number, atomic mass and atomic radius. Trends on the Periodic Table: Students learn to describe the pattern in atomic number, atomic mass, atomic ...

This lesson utilizes an adaptation of the board game Periodic: A Game of the Elements to help students better understand both general periodic trends and the law of conservation of energy. This ...

Measurements of an artificial radioactive element called lawrencium could revive an arcane controversy over the element’s position in the periodic table — and the structure of the table itself. An ...