Element 38
Strontium
Alkaline earth
Strontium (Sr) is in the s-block of the periodic table — group 2, period 5.
Strontium is a chemical element with symbol Sr and atomic number 38.
Key data
- Atomic number
- 38
- Atomic mass
- 87.621 u
- Group / Period
- 2 / 5
- Block
- s-block
- Phase at STP
- Solid
- Density
- 2.64 g/cm³
- Melting point
- 776.9 °C
- Boiling point
- 1376.8 °C
- Electron configuration
- [Kr] 5s2
Periodic table block
Strontium is in the s-block (group 2, period 5). Elements land in the s-block when their highest-energy electrons fill an s subshell — this includes hydrogen, helium, and the reactive metals on the far left of the table.
New to this? Periodic table blocks explained: s, p, d, and f
Common uses
- •Red fireworks
- •Old CRT screens
- •Bone-seeking isotope
Discovery
Year: 1808
Discovered by: William Cruickshank (chemist)
Frequently asked questions
What is the atomic number of Strontium?
Strontium has atomic number 38. Its symbol is Sr and its atomic mass is 87.621 u.
What category of element is Strontium?
Strontium is classified as alkaline earth. It sits in group 2, period 5 of the periodic table.
What block of the periodic table is Strontium in?
Strontium is in the s-block (group 2, period 5). Its highest-energy electrons occupy the s subshell — you can see this in its electron configuration, [Kr] 5s2.
What is Strontium used for?
Common uses of Strontium include: Red fireworks, Old CRT screens, Bone-seeking isotope.
When was Strontium discovered?
Strontium was discovered in 1808 by William Cruickshank (chemist).
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