Science
What is The periodic table?
The periodic table is a chart that organizes all the known chemical elements by their atomic number and shared properties. It lets scientists predict how elements behave and react.
See it, don’t just read it.
Watch a 2-minute lesson with voice + animation that explains the periodic table.
Key things to understand
- 1Elements are arranged by increasing number of protons (atomic number).
- 2Columns (groups) share similar chemical properties; rows are periods.
- 3Position predicts reactivity, bonding, and whether an element is a metal, nonmetal, or metalloid.
- 4It was devised by Dmitri Mendeleev, who even predicted undiscovered elements.
Frequently asked questions
- How is the periodic table organized?
- By atomic number, with elements of similar properties grouped in vertical columns.
- What are groups and periods?
- Groups are the columns (similar properties); periods are the rows (same number of electron shells).
- Who created the periodic table?
- Dmitri Mendeleev in 1869, arranging elements so patterns in their properties lined up.