Energy & Green Tech

Building a better, cheaper battery for power grids

Batteries do the heavy lifting to store excess solar energy on power grids for use after sundown, but to operate, they also rely on pricey elements like platinum.

Engineering

World's first LED lights developed from rice husks

Milling rice to separate the grain from the husks produces about 100 million tons of rice husk waste globally each year. Scientists searching for a scalable method to fabricate quantum dots have developed a way to recycle ...

Energy & Green Tech

Hybrid redox-flow battery with a long cycle life

Redox‑flow batteries store electrical energy in chemical compounds that are dissolved in an electrolyte. They are a particularly promising alternative to lithium‑ion batteries as stationary energy storage. A team headed ...

Internet

Google Scholar renders documents not in English invisible

The visibility of scientific articles and conference papers is conditional upon being easily found in academic search engines, especially Google Scholar. To enhance this visibility, search engine optimization (SEO) has been ...

Energy & Green Tech

New electrocatalysts to produce ethanol more efficiently

In recent years, researchers worldwide have been exploring new methods of producing ethanol, a chemical compound that is extensively used in a variety of industrial settings. One way to produce this compound is via what is ...

Energy & Green Tech

Physicists create highly efficient rocket fuel

Scientists at the Faculty of Physics and Engineering, working with the Tomsk company Scientific and Production Center Chemical Technologies, have created and tested an improved model of a hybrid rocket engine. The team synthesized ...

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Chemical compound

A chemical compound is a pure chemical substance consisting of two or more different chemical elements that can be separated into simpler substances by chemical reactions and that have a unique and defined chemical structure. Chemical compounds consist of a fixed ratio of atoms that are held together in a defined spatial arrangement by chemical bonds. Chemical compounds can be compound molecules held together by covalent bonds, salts held together by ionic bonds, metallic compounds held together by metallic bonds, or complexes held together by coordinate covalent bonds. Substances such as pure chemical elements and elemental molecules consisting of multiple atoms of a single element (such as H2, S8, etc.) are not considered chemical compounds.

Elements form compounds to become more stable. They become stable when they have the maximum number of possible electrons in their outermost energy level, which is normally two or eight valence electrons. This is the reason that noble gases do not frequently react: they already possess eight valence electrons (the exception being helium, which requires only two valence electrons to achieve stability).

This text uses material from Wikipedia, licensed under CC BY-SA