Topics (349k) Articles (361k) Users (420) Discussions (237) Comments (383) Files (12k) New article
Thulium (Tm) is a chemical element with the atomic number 69. It has several isotopes, of which the most notable are: 1. **Tl-169**: This is the most stable and abundant isotope of thulium, making up nearly all naturally occurring thulium. It has a half-life of 1,457 years and is stable. 2. **Tl-168**: This isotope is radioactive and has a half-life of about 93 minutes.
Thorium is a radioactive element with several isotopes, the most notable of which are: 1. **Thorium-232 (Th-232)**: This is the most abundant and stable isotope of thorium, making up about 99.98% of naturally occurring thorium. It has a half-life of approximately 14.05 billion years and is used in nuclear reactors and as a source material for nuclear fuel.
Thallium (Tl) has several isotopes, which are variants of the element with the same number of protons but different numbers of neutrons. Naturally occurring thallium has two stable isotopes: 1. **Thallium-203 (Tl-203)**: - Number of protons: 81 - Number of neutrons: 122 - Natural abundance: About 29.5%.
Terbium (Tb) is a chemical element with the atomic number 65. It has several isotopes, but only a few are stable. The most important isotopes of terbium include: 1. **Terbium-159 (Tb-159)**: This is the only stable isotope of terbium. It comprises about 100% of naturally occurring terbium.
Tennessine (Ts) is a synthetic element with the atomic number 117. As of now, there are no stable isotopes of tennessine, and all of its isotopes are radioactive. The isotopes of tennessine that have been identified include: 1. **Tennessine-294 (Ts-294)**: This is the most stable isotope of tennessine, with a half-life of approximately 78 milliseconds.
Tellurium (Te) has several isotopes, both stable and radioactive. The most common isotopes of tellurium are: 1. **Stable Isotopes:** - **Te-120**: The most abundant stable isotope, constituting about 33% of natural tellurium. - **Te-122**: Another stable isotope, making up about 52% of natural tellurium.
Technetium (Tc) is a chemical element with atomic number 43 and is notable for being the first artificially produced element. It has several isotopes, with the most significant ones being: 1. **Technetium-97 (Tc-97)**: This isotope has a half-life of about 4.2 million years and is one of the more stable isotopes. It is produced in trace amounts in nuclear reactors and is used in some medical applications.
Tantalum has two stable isotopes: **Tantalum-181 (Ta-181)** and **Tantalum-180 (Ta-180)**. The most abundant isotope is Ta-181, which constitutes almost all naturally occurring tantalum.
Sulfur has several isotopes, which are variants of the sulfur atom that have the same number of protons but different numbers of neutrons. The most common isotopes of sulfur are: 1. **Sulfur-32 (²³²S)**: This is the most abundant isotope, accounting for about 95% of naturally occurring sulfur. It has 16 protons and 16 neutrons.
Strontium has several isotopes, but the most notable ones are: 1. **Strontium-84 (Sr-84)**: This is the most abundant stable isotope of strontium, making up about 0.56% of naturally occurring strontium. 2. **Strontium-86 (Sr-86)**: This is another stable isotope, comprising about 9.86% of natural strontium.
Sodium (Na) has several isotopes, but the most notable ones are: 1. **Sodium-23 (Na-23)**: This is the only stable isotope of sodium and accounts for almost all naturally occurring sodium. It has 11 protons and 12 neutrons. 2. **Sodium-22 (Na-22)**: This is a radioactive isotope of sodium with a half-life of about 2.6 years.
Silver has several isotopes, but the two most notable ones are: 1. **Silver-107 (\(^{107}\)Ag)**: This is the most stable and abundant isotope of silver, comprising about 51.8% of natural silver. Silver-107 has a nuclear spin of 1/2 and is used in various applications, including in certain types of nuclear magnetic resonance (NMR) spectroscopy.
Silicon has several isotopes, which are variations of the silicon atom that have the same number of protons (14) but different numbers of neutrons. The stable isotopes of silicon are: 1. **Silicon-28 (Si-28)**: This is the most abundant isotope, making up about 97.2% of natural silicon. It has 14 protons and 14 neutrons.
Selenium has several isotopes, which are variations of the element that have the same number of protons but different numbers of neutrons. The most stable and common isotopes of selenium are: 1. **Selenium-74 (Se-74)**: This isotope has 34 protons and 40 neutrons and is one of the most abundant isotopes of selenium.
Seaborgium (Sg) is a synthetic element with atomic number 106. It is part of the transactinide series and was first synthesized in 1974. Due to its very short half-life, seaborgium has no stable isotopes. The known isotopes of seaborgium are all radioactive.
Samarium (Sm) is a chemical element with the atomic number 62. It has several isotopes, with the most stable and common ones being: 1. **Samarium-144 (^144Sm)**: This isotope has a half-life of about journalists days and is one of the most stable isotopes of samarium.
Rutherfordium (Rf) is a synthetic element with the atomic number 104. It has no stable isotopes, and all of its isotopes are radioactive. The most notable isotopes of rutherfordium include: 1. **Rutherfordium-261**: This is the most stable isotope, with a half-life of about 2.5 minutes. 2. **Rutherfordium-260**: This isotope has a half-life of approximately 2.2 minutes.
Ruthenium has several isotopes, with a total of 7 naturally occurring and synthetic isotopes known. Here are some of the notable isotopes of ruthenium: 1. **Ruthenium-96 (Ru-96)**: This is the most stable and abundant isotope, with a half-life of about 373.59 days. It primarily decays by beta decay.
Rubidium (Rb) has several known isotopes, with the most notable ones being rubidium-85 (¹⁸⁵Rb) and rubidium-87 (¹⁸⁷Rb). Here are some details about these isotopes: 1. **Rubidium-85 (¹⁸⁵Rb)**: - **Natural Abundance**: Approximately 72.2% of natural rubidium is ¹⁸⁵Rb.
Pinned article: Introduction to the OurBigBook Project
Welcome to the OurBigBook Project! Our goal is to create the perfect publishing platform for STEM subjects, and get university-level students to write the best free STEM tutorials ever.
Everyone is welcome to create an account and play with the site: ourbigbook.com/go/register. We belive that students themselves can write amazing tutorials, but teachers are welcome too. You can write about anything you want, it doesn't have to be STEM or even educational. Silly test content is very welcome and you won't be penalized in any way. Just keep it legal!
Intro to OurBigBook
. Source. We have two killer features:
- topics: topics group articles by different users with the same title, e.g. here is the topic for the "Fundamental Theorem of Calculus" ourbigbook.com/go/topic/fundamental-theorem-of-calculusArticles of different users are sorted by upvote within each article page. This feature is a bit like:
- a Wikipedia where each user can have their own version of each article
- a Q&A website like Stack Overflow, where multiple people can give their views on a given topic, and the best ones are sorted by upvote. Except you don't need to wait for someone to ask first, and any topic goes, no matter how narrow or broad
This feature makes it possible for readers to find better explanations of any topic created by other writers. And it allows writers to create an explanation in a place that readers might actually find it.
Figure 1. Screenshot of the "Derivative" topic page. View it live at: ourbigbook.com/go/topic/derivativeVideo 2. OurBigBook Web topics demo. Source. - local editing: you can store all your personal knowledge base content locally in a plaintext markup format that can be edited locally and published either:This way you can be sure that even if OurBigBook.com were to go down one day (which we have no plans to do as it is quite cheap to host!), your content will still be perfectly readable as a static site.
- to OurBigBook.com to get awesome multi-user features like topics and likes
- as HTML files to a static website, which you can host yourself for free on many external providers like GitHub Pages, and remain in full control
Figure 2. You can publish local OurBigBook lightweight markup files to either OurBigBook.com or as a static website.
Figure 3. Visual Studio Code extension installation.
Figure 5. . You can also edit articles on the Web editor without installing anything locally. Video 3. Edit locally and publish demo. Source. This shows editing OurBigBook Markup and publishing it using the Visual Studio Code extension. 
- Infinitely deep tables of contents:
All our software is open source and hosted at: github.com/ourbigbook/ourbigbook
Further documentation can be found at: docs.ourbigbook.com
Feel free to reach our to us for any help or suggestions: docs.ourbigbook.com/#contact