Barium vs. Strontium

Attribute	Barium	Strontium
Atomic Number	56	38
Symbol	Ba	Sr
Atomic Mass	137.33	87.62
Electron Configuration	[Xe] 6s2	[Kr] 5s2
Group	Alkaline Earth Metal	Alkaline Earth Metal
Period	6	5
Block	s	s
Electronegativity	0.89	0.95
Ionization Energy	502.9 kJ/mol	549.5 kJ/mol
Atomic Radius	215 pm	215 pm
Melting Point	727°C	769°C
Boiling Point	1897°C	1384°C
Density	3.51 g/cm³	2.64 g/cm³

Introduction

Barium and strontium are two chemical elements that belong to the alkaline earth metals group in the periodic table. Both elements share similar properties due to their position in the same group, but they also have distinct characteristics that set them apart. In this article, we will explore and compare the attributes of barium and strontium, including their physical properties, chemical reactivity, occurrence in nature, and various applications.

Physical Properties

Barium is a soft, silvery-white metal with a melting point of 727°C and a boiling point of 1,897°C. It is highly reactive and easily oxidizes in air, forming a protective oxide layer. Strontium, on the other hand, is also a soft, silvery-white metal but has a slightly lower melting point of 769°C and a boiling point of 1,384°C. It is less reactive than barium and tarnishes in air, forming a yellowish oxide layer.

Both elements have relatively high densities, with barium having a density of 3.62 g/cm³ and strontium having a density of 2.64 g/cm³. Barium is slightly denser than strontium, which contributes to its use in various applications where high-density materials are required. Additionally, both elements are good conductors of electricity and heat, making them valuable in certain industries.

Chemical Reactivity

Barium and strontium exhibit different levels of chemical reactivity. Barium is highly reactive and readily reacts with water, oxygen, and many other elements. It reacts vigorously with water, producing barium hydroxide and hydrogen gas. Strontium, on the other hand, is less reactive than barium but still reacts with water, albeit at a slower rate. It also reacts with oxygen, forming strontium oxide.

Both elements have a strong affinity for sulfur, forming sulfides when heated with sulfur compounds. Barium sulfide (BaS) and strontium sulfide (SrS) are commonly used in the production of luminous paints and cathode ray tubes. However, due to their reactivity, both barium and strontium need to be handled with caution to prevent any potential hazards.

Occurrence in Nature

Barium and strontium are both naturally occurring elements, although they are not as abundant as some other elements. Barium is primarily found in the mineral barite (barium sulfate) and can also be found in some igneous rocks and mineral springs. Strontium, on the other hand, is mainly found in the mineral celestite (strontium sulfate) and can also be found in seawater and certain minerals.

Both elements are not considered essential for living organisms, but they can be taken up by plants and animals. Barium can accumulate in the body and may have toxic effects, while strontium is known to replace calcium in bones, which can affect bone health. However, in controlled amounts, both elements have various applications in industry and technology.

Applications

Barium and strontium find applications in a wide range of industries and technologies. Barium compounds, such as barium sulfate, are used in the production of X-ray contrast agents for medical imaging. Barium titanate is a ferroelectric material used in the production of capacitors, transducers, and other electronic devices. Barium is also used in the manufacture of fireworks to produce green colors.

Strontium compounds have diverse applications as well. Strontium carbonate is used in the production of glass for cathode ray tubes and optical materials. Strontium aluminate is a phosphorescent material used in glow-in-the-dark products, such as watch dials and emergency exit signs. Strontium is also used in the production of flares and fireworks to create vibrant red colors.

Furthermore, both barium and strontium are used in the field of medicine. Barium sulfate suspensions are commonly used in gastrointestinal imaging procedures, such as barium meals and barium enemas. Strontium ranelate, a strontium salt, has been used in the treatment of osteoporosis to improve bone density and reduce the risk of fractures.

Conclusion

In conclusion, barium and strontium are two alkaline earth metals that share some similarities but also have distinct attributes. While both elements are soft, silvery-white metals with high densities, they differ in terms of melting and boiling points. Barium is more reactive than strontium and readily reacts with water, while strontium exhibits slower reactivity. Both elements occur naturally but are not as abundant as some other elements. They find applications in various industries, including medicine, electronics, and pyrotechnics. Understanding the attributes of barium and strontium allows us to appreciate their unique properties and utilize them effectively in different fields.