Strontium: Occurrence, Properties, Uses and Isotopes of Strontium

Introduction

  • Strontium is an alkaline earth metal located in group number 2A of the periodic table.
  • Its atomic number is 38 whereas its atomic mass is 87.62. It has 38 electrons.
  • Strontium has 38 protons and 50 neutrons in its nucleus.
  • Strontium is represented by the symbol “Sr”.
Naming and History

Strontium was named after the town Strontian in Scotland where it was mined.

  • Adair Crawford

In 1787, an unusual rock that had been discovered in a lead mine at Strontian, Scotland, was examined by Adair Crawford, an Edinburgh medical professional. He understood it was a new mineral including an unknown ‘earth’ which he called Strontia.

  • Thomas Charles Hope

In 1791, another Edinburgh man, Thomas Charles Hope, made a fuller investigation of it as well as showed it was a new element. He also observed that it created the flame of candlelight to burn red.

  • Sir Humphry Davy

Strontium metal was first separated in 1808 by Sir Humphry Davy operating in London by electrolysis. He blended magnesium oxide to a paste with (most likely) strontium sulfate. He made a depression in the paste and put mercury metal there to function as an electrode. Platinum was made use of as a counter electrode.

When electricity was passed through the paste, a strontium-mercury amalgam formed at the mercury electrode. Davy removed the mercury from the amalgam by heating it to leave strontium metal.

Occurrence of Strontium

Occurrence-of-Strontium

Strontium is highly reactive so never occurs freely in its elemental form instead it is present in combination with other elements in ores and minerals. Igneous rocks contain 0.034% of strontium. Other minerals containing strontium are celestite (SrSO4) and carbonate strontianite (SrCO3).

Properties of Strontium

Strontium is a soft, silver-yellow, alkaline-earth metal. It has three allotropic crystalline types and has a striking resemblance with calcium and barium. Strontium reacts vigorously with water and spontaneously ignites in air, so it has to be kept out of contact with air and water.

Carefully powdered strontium metal is adequately responsive to ignite in air. As a result of its propensity for oxidation and also ignition, strontium is normally stored under kerosene. Strontium salts color flame crimson and are made use of in fireworks and flares.

The melting point of strontium is 777°C and its boiling point is 1382°C. It has a density of 2.64 grams per cubic centimeter. It exists as solid at room temperature.

Strontium in Biological Systems

Strontium is considered to be non-toxic. It has no known significant role in humans. Some marine organisms such as shelled animals and corals have strontium incorporated into their hard mass.

Strontium- 90 is a radioactive element and can have adverse effects especially in young children as it is absorbed in bones.

Uses of Strontium

Uses-of-Strontium

  • It is used as a getter to remove traces of residual gases from vacuum tubes.
  • Strontium is best recognized for the fantastic reds its salts provide to fireworks and flares.
  • Strontium oxide is used to increase the quality of ceramic glazes.
  • Strontium is utilized in the manufacture of color tv picture tubes.
  • Strontium titanate is very soft however has an extremely high refractive index as well as an optical dispersion more than that of the diamond.
Further Reading:  Basic Concepts of Mole, Avogadro’s Number and Molar Volume
Isotopes of Strontium

There are 28 known isotopes of strontium from mass ranging from 75 to 102. There are four naturally occurring stable isotopes. The most abundant one is Sr- 88 which is 82% abundant.

  • Sr- 90 is a radioactive isotope and widely used in nuclear reactors as a high-energy beta emitter. Some studies show its use in cancer therapy.

MCQs

  • What is the atomic number of strontium?
    • A) 38
    • B) 87.62
    • C) 50
    • D) 2A
    • Answer: A
  • Who discovered strontium and named it after the town of Strontian in Scotland?
    • A) Adair Crawford
    • B) Thomas Charles Hope
    • C) Sir Humphry Davy
    • D) None of the above
    • Answer: A
  • In what year was strontium first separated as a metal by Sir Humphry Davy?
    • A) 1787
    • B) 1791
    • C) 1808
    • D) 1820
    • Answer: C
  • What are the two minerals mentioned as sources of strontium?
    • A) Quartz and feldspar
    • B) Celestite and strontianite
    • C) Halite and gypsum
    • D) Hematite and magnetite
    • Answer: B
  • Which metal does strontium closely resemble in terms of properties?
    • A) Calcium
    • B) Iron
    • C) Sodium
    • D) Aluminum
    • Answer: A
  • How does strontium react with water?
    • A) Reacts slowly
    • B) Reacts vigorously
    • C) Does not react
    • D) Explodes
    • Answer: B
  • What color does strontium salts impart to flames?
    • A) Blue
    • B) Yellow
    • C) Green
    • D) Crimson
    • Answer: D
  • What is the melting point of strontium?
    • A) 777°C
    • B) 1000°C
    • C) 500°C
    • D) 2000°C
    • Answer: A
  • What is the primary use of strontium in color television picture tubes?
    • A) Enhancing conductivity
    • B) Improving resolution
    • C) Enhancing color quality
    • D) Strengthening glass
    • Answer: C
  • How many naturally occurring stable isotopes does strontium have?
    • A) 2
    • B) 3
    • C) 4
    • D) 5
    • Answer: C
  • Which is the most abundant stable isotope of strontium?
    • A) Sr-88
    • B) Sr-90
    • C) Sr-98
    • D) Sr-100
    • Answer: A
  • What is the percentage abundance of Sr-88?
    • A) 75%
    • B) 82%
    • C) 90%
    • D) 100%
    • Answer: B
  • Which isotope of strontium is widely used in nuclear reactors?
    • A) Sr-88
    • B) Sr-90
    • C) Sr-98
    • D) Sr-100
    • Answer: B
  • What type of radiation does Sr-90 emit?
    • A) Alpha
    • B) Beta
    • C) Gamma
    • D) Neutron
    • Answer: B
  • In what field is Sr-90 sometimes used according to some studies?
    • A) Agriculture
    • B) Energy production
    • C) Medicine
    • D) Construction
    • Answer: C
  • Which scientist made the discovery of strontium and called it “Strontia”?
    • A) Adair Crawford
    • B) Thomas Charles Hope
    • C) Sir Humphry Davy
    • D) Albert Einstein
    • Answer: A
  • How did Sir Humphry Davy separate strontium for the first time?
    • A) By distillation
    • B) By electrolysis
    • C) By filtration
    • D) By crystallization
    • Answer: B
  • What is the common color strontium salts provide to fireworks?
    • A) Blue
    • B) Green
    • C) Yellow
    • D) Red
    • Answer: D
  • Which mineral contains strontium in combination with sulfate?
    • A) Celestite
    • B) Halite
    • C) Quartz
    • D) Gypsum
    • Answer: A
  • Why is strontium commonly stored under kerosene?
    • A) To prevent oxidation
    • B) To prevent ignition
    • C) To prevent contamination
    • D) To enhance reactivity
    • Answer: A
  • Which is the most closely resembling element to strontium in the periodic table?
    • A) Calcium
    • B) Sodium
    • C) Iron
    • D) Magnesium
    • Answer: A
  • What is the primary use of strontium in ceramic glazes?
    • A) Enhancing color
    • B) Improving hardness
    • C) Increasing density
    • D) Reducing porosity
    • Answer: A
  • What is the boiling point of strontium?
    • A) 777°C
    • B) 1382°C
    • C) 1000°C
    • D) 2000°C
    • Answer: B
  • What are the components of the paste used by Sir Humphry Davy in his strontium isolation experiment?
    • A) Magnesium oxide and strontium sulfate
    • B) Magnesium sulfate and calcium oxide
    • C) Magnesium chloride and strontium nitrate
    • D) Magnesium carbonate and barium sulfate
    • Answer: A
Further Reading:  Filtration - Definition, Uses, Methods & Examples of filtration

 

FAQs (Frequently Asked Questions) about Strontium

  1. What is strontium, and where is it located in the periodic table?
    • Strontium is an alkaline earth metal situated in group number 2A of the periodic table.
  2. How was strontium named, and what is its historical background?
    • Strontium derived its name from the town of Strontian in Scotland, where it was initially mined. Its discovery and characterization involved contributions from figures like Adair Crawford, Thomas Charles Hope, and Sir Humphry Davy.
  3. Where is strontium commonly found?
    • Strontium typically occurs in combination with other elements in ores and minerals. It is commonly found in igneous rocks and minerals such as celestite (SrSO4) and strontianite (SrCO3).
  4. What are the notable properties of strontium?
    • Strontium is a soft, silver-yellow metal with high reactivity. It reacts vigorously with water and spontaneously ignites in air. Its salts impart a crimson color to flames, making them useful in fireworks.
  5. What are the uses of strontium?
    • Strontium finds applications in various fields, including vacuum tube technology, fireworks, ceramic glazes, and color TV picture tubes. Strontium titanate, a compound of strontium, is known for its optical properties.
  6. Is strontium harmful to biological systems?
    • Strontium is generally considered non-toxic, but its radioactive isotope, strontium-90, can have adverse effects, especially when absorbed into bones. Some marine organisms incorporate strontium into their hard mass.
  7. How many isotopes does strontium have, and what are their characteristics?
    • Strontium has 28 known isotopes, with four naturally occurring stable isotopes. The most abundant stable isotope is Sr-88, while Sr-90 is a radioactive isotope widely used in nuclear reactors.
  8. Are there any potential medical applications of strontium?
    • Some studies suggest the use of strontium-90 in cancer therapy due to its high-energy beta emission properties.
  9. How was strontium first isolated as a metal?
    • Sir Humphry Davy succeeded in isolating strontium metal through electrolysis in 1808, using a paste of magnesium oxide and strontium sulfate.
  10. What precautions are necessary when handling strontium?
    • Due to its reactivity, strontium should be kept away from air and water. It is often stored under kerosene to prevent oxidation.

 

Summary

This tutorial provides an in-depth exploration of strontium, an alkaline earth metal represented by the symbol “Sr” on the periodic table. Below is a structured summary of its contents:

  1. Introduction:
    • Provides fundamental information about strontium, including its atomic number, atomic mass, and location in the periodic table.
  2. Naming and History:
    • Traces the historical background of strontium, from its discovery in the town of Strontian, Scotland, to the contributions of key figures like Adair Crawford and Sir Humphry Davy.
  3. Occurrence of Strontium:
    • Discusses the occurrence of strontium in nature, its reactivity, and its presence in minerals such as celestite and strontianite.
  4. Properties of Strontium:
    • Explores the physical and chemical properties of strontium, including its appearance, reactivity with water and air, and its uses in fireworks.
  5. Strontium in Biological Systems:
    • Examines the role of strontium in biological systems, highlighting its non-toxic nature and potential risks associated with its radioactive isotope, strontium-90.
  6. Uses of Strontium:
    • Details the various applications of strontium, from its use in vacuum tubes to its role in enhancing color quality in fireworks and ceramic glazes.
  7. Isotopes of Strontium:
    • Provides insights into the isotopic composition of strontium, focusing on stable and radioactive isotopes like Sr-88 and Sr-90, and their significance in nuclear reactors and medical applications.
  8. Further Reading:
    • Offers additional resources for readers interested in exploring related topics further.
Further Reading:  Zinc: Occurrence, Properties, Uses and Isotopes of Zinc

This structured summary aims to provide a comprehensive overview of the tutorial’s content, facilitating understanding and retention of key concepts related to strontium.