Darmstadtium is a synthetic element with the symbol Ds and atomic number 110. It is part of the transactinide series of elements and was first synthesized in 1994. As of now, darmstadtium has no stable isotopes; all of its isotopes are radioactive.
Curium (Cm) is an actinide element with atomic number 96. It has several isotopes, with the most notable being: 1. **Curium-242 (Cm-242)**: This is the most stable isotope of curium and has a half-life of about 162.8 days. It decays primarily by alpha emission. 2. **Curium-244 (Cm-244)**: This isotope has a half-life of approximately 18.
Copper has two stable isotopes: \( ^{63}Cu \) and \( ^{65}Cu \). 1. **\( ^{63}Cu \)**: This isotope has 29 protons and 34 neutrons, comprising about 69% of naturally occurring copper. Its atomic mass is approximately 62.93 u.
Copernicium (Cn) is a synthetic element with the atomic number 112. It is a member of the group 10 elements in the periodic table. As of now, there are currently a few known isotopes of copernicium, but all are highly unstable and radioactive. The most notable isotopes of copernicium include: 1. **Copernicium-277 (\(^{277}\)Cn)**: This isotope has a half-life of about 0.
Cobalt has several isotopes, but the most notable ones are: 1. **Cobalt-59 (^59Co)** - This is the only stable isotope of cobalt, making up nearly 100% of naturally occurring cobalt. It has 27 protons and 32 neutrons. 2. **Cobalt-60 (^60Co)** - This is a radioactive isotope with a half-life of about 5.27 years.
Chromium has several isotopes, which are variants of the element with the same number of protons but different numbers of neutrons. The most notable isotopes of chromium are: 1. **Chromium-50 (⁵⁰Cr)**: This is the most abundant isotope, making up about 4.3% of natural chromium. It has 24 protons and 26 neutrons.
Chlorine has two stable isotopes, which are: 1. **Chlorine-35 (¹⁷Cl)**: This isotope has 17 neutrons and is the more abundant of the two, making up about 76% of naturally occurring chlorine. 2. **Chlorine-37 (¹⁹Cl)**: This isotope has 20 neutrons and accounts for about 24% of natural chlorine.
Cerium (Ce) is a chemical element with atomic number 58 and belongs to the lanthanide series. It has several isotopes, which are variants of the element with the same number of protons but a different number of neutrons. The isotopes of cerium are: 1. **^136Ce** - Stable isotope with 78 neutrons. 2. **^138Ce** - Stable isotope with 80 neutrons.
Carbon has three main isotopes: carbon-12 (\(^{12}\text{C}\)), carbon-13 (\(^{13}\text{C}\)), and carbon-14 (\(^{14}\text{C}\)). Each isotope has the same number of protons but a different number of neutrons, leading to differences in their atomic masses.
Californium (Cf) has several isotopes, of which the most notable are: 1. **Californium-252 (Cf-252)**: This isotope is one of the most prominent, with a half-life of about 2.645 years. It is a powerful neutron emitter and is used in various applications, including neutron radiography, chemotherapy, and as a neutron source in scientific research.
Calcium has several isotopes, which are variants of the element that have the same number of protons but different numbers of neutrons. The isotopes of calcium are: 1. **Calcium-40 (⁴⁰Ca)** - The most abundant and stable isotope, making up about 97% of naturally occurring calcium. It has 20 protons and 20 neutrons.
Caesium (Cs) has several isotopes, with the most stable and commonly known ones being: 1. **Cs-133**: This is the most stable isotope of caesium and is used as the standard for the definition of the second in the International System of Units (SI). Cs-133 has a half-life of stable, meaning it does not undergo radioactive decay.
Cadmium (Cd) has several isotopes, with the most stable and common ones being: 1. **Cadmium-106 (Cd-106)**: This isotope is stable and has a natural abundance of about 1.25%. 2. **Cadmium-108 (Cd-108)**: Also stable, this isotope has an abundance of about 0.89%. 3. **Cadmium-110 (Cd-110)**: Another stable isotope, it comprises roughly 12.
Bromine has several isotopes, but the two most notable ones are: 1. **Bromine-79 (Br-79)**: This is the most stable and abundant isotope of bromine, making up about 50.5% of naturally occurring bromine. It has a half-life that is stable (not radioactive), and it consists of 35 protons and 44 neutrons.
Boron has two stable isotopes and several unstable isotopes. The two stable isotopes of boron are: 1. **Boron-10 (¹⁰B)**: This isotope has 5 protons and 5 neutrons, and it constitutes about 19.9% of naturally occurring boron. It is often used in applications such as neutron capture therapy for treating cancer and in various nuclear applications.
Bohrium (Bh) is a synthetic element with the atomic number 107. It was first synthesized in 1981 and is named after the physicist Niels Bohr. Currently, several isotopes of bohrium have been produced, but they are all radioactive and have relatively short half-lives. The most notable isotopes of bohrium include: 1. **Bohrium-262 (Bh-262)**: This isotope has a half-life of about 5.6 milliseconds.
Bismuth (Bi) has several isotopes, but the most notable ones are: 1. **Bismuth-209 (Bi-209)**: This is the most stable and abundant isotope of bismuth, constituting nearly 100% of natural bismuth. It has a half-life of about 1.9 x 10^19 years, making it effectively stable for practical purposes.
Beryllium has several isotopes, but the most significant ones are: 1. **Beryllium-7 (Be-7)**: This isotope has a mass number of 7 and is a radioactive isotope with a half-life of about 53.1 days. It is produced in the atmosphere through the interaction of cosmic rays with nitrogen and oxygen. Beryllium-7 decays by beta decay into lithium-7.
Berkelium (Bk) is a synthetic element with atomic number 97 and is part of the actinide series. It has several isotopes, the most notable of which are: 1. **Berkelium-247 (Bk-247)**: This is the most stable and commonly referenced isotope of berkelium, with a half-life of approximately 1,380 days (about 3.8 years).
Barium has several isotopes, which are variants of the element that have the same number of protons but different numbers of neutrons. The most stable and common isotopes of barium are: 1. **Barium-130 (Ba-130)**: This is the most abundant isotope, comprising about 7.1% of natural barium. 2. **Barium-132 (Ba-132)**: This isotope is also stable and is about 0.

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!
We have two killer features:
  1. 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-calculus
    Articles 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/derivative
  2. 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.
    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.
  3. https://raw.githubusercontent.com/ourbigbook/ourbigbook-media/master/feature/x/hilbert-space-arrow.png
  4. Infinitely deep tables of contents:
    Figure 6.
    Dynamic article tree with infinitely deep table of contents
    .
    Descendant pages can also show up as toplevel e.g.: ourbigbook.com/cirosantilli/chordate-subclade
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