Strontium Atomic Number


Strontium has an atomic number of 38, which means it has 38 protons. In a neutral atom, an equal number of protons and electrons cancel each other out, resulting in a net charge of zero. As a result, one neutral atom of strontium must have 38 electrons. These electrons are arranged in energy levels around the nucleus. Strontium (Sr), chemical element, one of the alkaline-earth metals of Group 2 (IIa) of the periodic table. It is used as an ingredient in red signal flares and phosphors and is the principal health hazard in radioactive fallout. Atomic number 38 atomic weight 87.62 melting point 769 °C (1,416 °F). Strontium has an atomic number of 38 and a mass number of 88. How many neutrons are in one atom of strontium? An atom of rubidium has 37 protons.

Element Strontium - Sr

Strontium 87 protons

Comprehensive data on the chemical element Strontium is provided on this page; including scores of properties, element names in many languages, most known nuclides of Strontium. Common chemical compounds are also provided for many elements. In addition technical terms are linked to their definitions and the menu contains links to related articles that are a great aid in one's studies.

Strontium Element

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Overview of Strontium

  • Atomic Number: 38
  • Group: 2
  • Period: 5
  • Series: Alkali Earth Metals

Strontium's Name in Other Languages

  • Latin: Strontium
  • Czech: Stroncium
  • Croatian: Stroncij
  • French: Strontium
  • German: Strontium - s
  • Italian: Stronzio
  • Norwegian: Strontium
  • Portuguese: Estrôncio
  • Russian: Стронций
  • Spanish: Estroncio
  • Swedish: Strontium

Atomic Structure of Strontium

Strontium 90 atomic number
  • Atomic Radius: 2.45Å
  • Atomic Volume: 33.7cm3/mol
  • Covalent Radius: 1.91Å
  • Cross Section (Thermal Neutron Capture) σa/barns: 1.28
  • Crystal Structure: Cubic face centered
  • Electron Configuration:
    1s2 2s2p6 3s2p6d10 4s2p6 5s2
  • Electrons per Energy Level: 2,8,18,8,2
    Shell Model
  • Ionic Radius: 1.12Å
  • Filling Orbital: 5s2
  • Number of Electrons (with no charge): 38
  • Number of Neutrons (most common/stable nuclide): 50
  • Number of Protons: 38
  • Oxidation States: 2
  • Valence Electrons: 5s2
    Electron Dot Model

Chemical Properties of Strontium

  • Electrochemical Equivalent: 1.635g/amp-hr
  • Electron Work Function: 2.59eV
  • Electronegativity: 0.95 (Pauling); 0.99 (Allrod Rochow)
  • Heat of Fusion: 8.3kJ/mol
  • Incompatibilities:
  • Ionization Potential
    • First: 5.695
    • Second: 11.03
    • Third: 43.6
  • Valence Electron Potential (-eV): 25.7

Physical Properties of Strontium

  • Atomic Mass Average: 87.62
  • Boiling Point: 1657K 1384°C 2523°F
  • Coefficient of lineal thermal expansion/K-1: 23E-6
  • Conductivity
    Electrical: 0.0762 106/cm Ω
    Thermal: 0.353 W/cmK
  • Density: 2.54g/cc @ 300K
  • Description:
    Soft silvery yellow metal that will burn if ignited in air.
  • Elastic Modulus:
    • Bulk: 12/GPa
    • Rigidity: 6.03/GPa
    • Youngs: 15.7/GPa
  • Enthalpy of Atomization: 163.2 kJ/mole @ 25°C
  • Enthalpy of Fusion: 9.16 kJ/mole
  • Enthalpy of Vaporization: 150 kJ/mole
  • Flammablity Class:
  • Freezing Point:see melting point
  • Hardness Scale
    • Mohs: 1.5
  • Heat of Vaporization: 144kJ/mol
  • Melting Point: 1042K 769°C 1416°F
  • Molar Volume: 33.7 cm3/mole
  • Physical State (at 20°C & 1atm): Solid
  • Specific Heat: 0.3J/gK
  • Vapor Pressure = [email protected]°C

Regulatory / Health

  • CAS Number
    • 7440-24-6
  • OSHAPermissible Exposure Limit (PEL)
    • No limits set by OSHA
  • OSHA PEL Vacated 1989
    • No limits set by OSHA
  • NIOSHRecommended Exposure Limit (REL)
    • No limits set by NIOSH
  • Levels In Humans:
    Note: this data represents naturally occuring levels of elements in the typical human, it DOES NOT represent recommended daily allowances.
    • Blood/mg dm-3: 0.031
    • Bone/p.p.m: 36-140
    • Liver/p.p.m: 0.05-0.36
    • Muscle/p.p.m: 0.12-0.35
    • Daily Dietary Intake: 0.8-5 mg
    • Total Mass In Avg. 70kg human: 320 mg
  • Discovery Year: 1790
  • Name Origin:
    From Strontian a small Scottish town.
  • Abundance of Strontium:
    • Earth's Crust/p.p.m.: 370
    • Seawater/p.p.m.:
      • Atlantic Suface: 7.6
      • Atlantic Deep: 7.7
      • Pacific Surface: 7.6
      • Pacific Deep: 7.7
    • Atmosphere/p.p.m.: N/A
    • Sun (Relative to H=1E12): 790
  • Sources of Strontium:
    Found in minerals celestite and strontianite. Annual world wide production is around 137,000 tons. Primary mining areas are UK, Tunisia, Russia, Germany, Mexico and USA.
  • Uses of Strontium:
    Used in flares and fireworks for crimson color. Also used in nuclear batteries in buoys and phosphorescent paint.
  • Additional Notes:
    A. Crawford first recognized strontium as an element in 1790, but it wasn't isolated until 1808 by Sir Humphry Davy in London England.

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A list of reference sources used to compile the data provided on our periodic table of elements can be found on the main periodic table page.

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Strontium Atomic Number An

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