We are independent & ad-supported. We may earn a commission for purchases made through our links.
Advertiser Disclosure
Our website is an independent, advertising-supported platform. We provide our content free of charge to our readers, and to keep it that way, we rely on revenue generated through advertisements and affiliate partnerships. This means that when you click on certain links on our site and make a purchase, we may earn a commission. Learn more.
How We Make Money
We sustain our operations through affiliate commissions and advertising. If you click on an affiliate link and make a purchase, we may receive a commission from the merchant at no additional cost to you. We also display advertisements on our website, which help generate revenue to support our work and keep our content free for readers. Our editorial team operates independently of our advertising and affiliate partnerships to ensure that our content remains unbiased and focused on providing you with the best information and recommendations based on thorough research and honest evaluations. To remain transparent, we’ve provided a list of our current affiliate partners here.

What is Cesium?

Mary McMahon
Updated May 21, 2024
Our promise to you
All The Science is dedicated to creating trustworthy, high-quality content that always prioritizes transparency, integrity, and inclusivity above all else. Our ensure that our content creation and review process includes rigorous fact-checking, evidence-based, and continual updates to ensure accuracy and reliability.

Our Promise to you

Founded in 2002, our company has been a trusted resource for readers seeking informative and engaging content. Our dedication to quality remains unwavering—and will never change. We follow a strict editorial policy, ensuring that our content is authored by highly qualified professionals and edited by subject matter experts. This guarantees that everything we publish is objective, accurate, and trustworthy.

Over the years, we've refined our approach to cover a wide range of topics, providing readers with reliable and practical advice to enhance their knowledge and skills. That's why millions of readers turn to us each year. Join us in celebrating the joy of learning, guided by standards you can trust.

Editorial Standards

At All The Science, we are committed to creating content that you can trust. Our editorial process is designed to ensure that every piece of content we publish is accurate, reliable, and informative.

Our team of experienced writers and editors follows a strict set of guidelines to ensure the highest quality content. We conduct thorough research, fact-check all information, and rely on credible sources to back up our claims. Our content is reviewed by subject-matter experts to ensure accuracy and clarity.

We believe in transparency and maintain editorial independence from our advertisers. Our team does not receive direct compensation from advertisers, allowing us to create unbiased content that prioritizes your interests.

Cesium is a rare metallic chemical element that is used in an assortment of industries. It also has a wide range of isotopes, many of which are radioactive. Since it is highly reactive, the element is not usually found in a pure form in nature; most of the world's supply comes from minerals and nuclear fission. Consumers do not generally interact directly with cesium or its isotopes, although they may own products which contain it as a component.

In appearance, cesium is soft and silvery white. It has the unusual property of being liquid at room temperature. The element is also extremely reactive, highly alkaline, and very electropositive. Cesium can react violently with water, ice, or moist air. It is identified with the symbol Cs on the periodic table of elements, and it has an atomic number of 55. The high reactivity of this element means that it appears in a number of compounds, some of which are toxic.

The discovery of cesium is credited to Gustav Kirchoff and Robert Bunsen in 1860. Using a spectrometer to analyze mineral water from Durkheim, Germany, the two men noted the existence of a previously unidentified element that emitted a distinctive bluish gray line on the spectrum. The men named the element after the Latin caesius, which means "bluish gray." By 1882, another chemist had managed to isolate metallic cesium. Writers of British English may be more familiar with the element as caesium.

In industry, cesium is used in atomic clocks, photoelectric cells, and in nuclear medicine. Some radioactive isotopes appear to be highly useful in cancer treatment. The element is also used as a catalyst to create certain desired chemical reactions, and it is used in various fields of scientific research. Compounds are available at fairly reasonable prices; in its pure form, itcan be quite expensive.

Radioactive cesium isotopes can enter the environment through the detonation of nuclear devices and through improperly controlled waste. These isotopes can permeate drinking water and rivers, potentially causing human health effects ranging from spasms to death, depending on the extent of exposure. Fortunately, cesium poisoning appears to be fairly rare, since a high concentration is required for toxicity to be reached. However, care should be used when handling the element and its isotopes because of its reactivity and toxicity.

All The Science is dedicated to providing accurate and trustworthy information. We carefully select reputable sources and employ a rigorous fact-checking process to maintain the highest standards. To learn more about our commitment to accuracy, read our editorial process.
Mary McMahon
By Mary McMahon

Ever since she began contributing to the site several years ago, Mary has embraced the exciting challenge of being a All The Science researcher and writer. Mary has a liberal arts degree from Goddard College and spends her free time reading, cooking, and exploring the great outdoors.

Discussion Comments
By anon301727 — On Nov 05, 2012

This information was very useful. Cesium is now my favorite element in the periodic table!

By qwertyq — On Jun 27, 2011

@anon157664 – Technically, you’re right on both accounts. Cesium is an Alkali Metal, which is defined as a highly reactive metal that doesn’t normally occur in nature. So yes, it’s a metal.

The author of the article probably wrote that Cesium is liquid at room temperature because the Cesium is in its liquid state at a rather low temperature: 83.3 degrees Fahrenheit.

For scientific purposes, “room temperature” is 72 degrees Fahrenheit. I’ve also seen it list as 73 degrees, but never as high as Cesium’s melting point. So yes, by scientific standards, Cesium is a solid at room temperature.

By anon157664 — On Mar 03, 2011

But I thought that Cesium was a metal and at room temperature it was a solid.

By anon109377 — On Sep 07, 2010

i think this was useful.

Mary McMahon
Mary McMahon

Ever since she began contributing to the site several years ago, Mary has embraced the exciting challenge of being a...

Learn more
All The Science, in your inbox

Our latest articles, guides, and more, delivered daily.

All The Science, in your inbox

Our latest articles, guides, and more, delivered daily.