law of conservation of matter
71radioactivity — /ray dee oh ak tiv i tee/, n. Physics, Chem. the phenomenon, exhibited by and being a property of certain elements, of spontaneously emitting radiation resulting from changes in the nuclei of atoms of the element. Also called activity. [1895… …
72Food web — A freshwater aquatic and terrestrial food web. A food web (or food cycle) depicts feeding connections (what eats what) in an ecological community. Ecologists can broadly lump all life forms into one of two categories called trophic levels: 1) the …
73energy conversion — ▪ technology Introduction the transformation of energy from forms provided by nature to forms that can be used by humans. Over the centuries a wide array of devices and systems has been developed for this purpose. Some of these energy …
74Timeline of chemistry — lists important works, discoveries, ideas, inventions, and experiments that significantly changed mankind s understanding of the composition of matter and of the interactions thereof, the modern science known as chemistry. The history of… …
75chemistry — /kem euh stree/, n., pl. chemistries. 1. the science that deals with the composition and properties of substances and various elementary forms of matter. Cf. element (def. 2). 2. chemical properties, reactions, phenomena, etc.: the chemistry of… …
76fluid mechanics — an applied science dealing with the basic principles of gaseous and liquid matter. Cf. fluid dynamics. [1940 45] * * * Study of the effects of forces and energy on liquids and gases. One branch of the field, hydrostatics, deals with fluids at… …
77Climate change mitigation — Fossil fuel related CO2 emissions compared to five of IPCC s emissions scenarios. The dips are related to global recessions. Data from IPCC SRES scenarios; …
78Negative mass — In theoretical physics, negative mass is a hypothetical concept of matter whose mass is of opposite sign to the mass of the normal matter. Such matter would violate one or more energy conditions and show some strange properties such as being… …
79Derivation of the Navier–Stokes equations — The intent of this article is to highlight the important points of the derivation of the Navier–Stokes equations as well as the application and formulation for different families of fluids. Contents 1 Basic assumptions 2 The material derivative 3 …
80chemical bonding — ▪ chemistry Introduction any of the interactions that account for the association of atoms into molecules, ions, crystals, and other stable species that make up the familiar substances of the everyday world. When atoms approach one another …
