Strontium (symbol Sr, atomic number 38) is an alkaline earth metal that gives fireworks their brilliant red colour. It is classified as a alkaline earth metal and sits in group 2, period 5 of the periodic table.
Overview
Strontium is the chemical element with atomic number 38 and the symbol Sr. With a standard atomic weight of 87.62, it is a alkaline earth metal. In the periodic table it occupies group 2 and period 5, and under standard conditions it is normally a solid. Strontium is an alkaline earth metal that gives fireworks their brilliant red colour.
Atomic structure
An atom of Strontium has 38 protons in its nucleus and, when neutral, 38 electrons arranged in the configuration [Kr] 5s2. Its standard atomic weight of 87.62 reflects the natural mix of its stable isotopes.
Discovery and place in the table
Strontium was discovered in 1790 by William Cruickshank. It follows Rubidium (Rb) and precedes Yttrium (Y) in order of atomic number.
| Atomic number | 38 |
|---|---|
| Symbol | Sr |
| Atomic mass | 87.62 |
| Category | Alkaline earth metal |
| Group | 2 |
| Period | 5 |
| Electron configuration | [Kr] 5s2 |
| Phase at STP | Solid |
| Discovered | 1790 (William Cruickshank) |