Medical research

'Exercise-in-a-pill' boosts athletic endurance by 70 percent

Every week, there seems to be another story about the health benefits of running. That's great—but what if you can't run? For the elderly, obese or otherwise mobility-limited, the rewards of aerobic exercise have long been ...

Oncology & Cancer

Tracing biological pathways

A new chemical process developed by a team of Harvard researchers greatly increases the utility of Positron Emission Tomography (PET) in creating real-time 3-D images of chemical process occurring inside the human body.

Medications

Non-psychotropic cannabinoids show promise for pain relief

Some cancers love bone. They thrive in its nutrient-rich environment while gnawing away at the very substrate that sustains them, all the while releasing inflammatory substances that cause pain—pain so severe that opioids ...

Health

Study suggests that being too clean can make people sick

Young people who are overexposed to antibacterial soaps containing triclosan may suffer more allergies, and exposure to higher levels of Bisphenol A among adults may negatively influence the immune system, a new University ...

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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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