Diabetes

New insight into the biology of insulin release

In a new study, Yale researchers challenge a long-held assumption about how insulin-producing cells in the pancreas sense and respond to glucose. Their findings could lead to changes in the way that scientists approach the ...

Medical research

Reinvigorating the clinical drug pipeline for TB

A research team led by scientists from the Broad Institute has uncovered a novel group of chemical inhibitors that can kill the bacteria that causes tuberculosis (TB). Importantly, these chemical compounds take aim at a previously ...

Immunology

Polysulfide donors strongly suppress inflammatory responses

Researchers from Japan have developed a new polysulfide donor: a chemical compound composed of chains of sulfur atoms that can artificially increase reactive sulfur species (chemically reactive molecules containing sulfur) ...

Oncology & Cancer

Balance of two enzymes linked to pancreatic cancer survival

Protein Kinase C (PKC) enzymes are crucial for a number of cellular activities, including cell survival, proliferation and migration—functions that must be carefully controlled lest cells get out of control and form a tumor. ...

Health

Arc welding fumes detrimental to human health

Working as part of an international group of toxicologists, scientists of the Far Eastern Federal University (FEFU) have found that harmful nanoparticles are formed in the process of arc welding using the most common types ...

Oncology & Cancer

Advancing gene therapy for skin cancer

One of the deadliest skin cancers, melanoma may be caused by overexposure to ultraviolet radiation from the sun or artificial sources such as tanning beds and sunlamps. The Melanoma Network of Canada reports that lifetime ...

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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).

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