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Cerium is a chemical element; it has symbol Ce and atomic number 58. It is a soft , ductile , and silvery-white metal that tarnishes when exposed to air. Cerium is the second element in the lanthanide series, and while it often shows the oxidation state of +3 characteristic of the series, it also has a stable +4 state that does not oxidize water.
[4] [5] Plate tectonics are needed for life over a long time span, and carbon-based life is important in the plate tectonics process. [6] Iron- and sulfur-based Anoxygenic photosynthesis life forms that lived from 3.80 to 3.85 billion years ago on Earth produced an abundance of black shale deposits. These shale deposits increase heat flow and ...
Because living systems involve net movement in terms of chemical movement or body movement, and lose energy in those movements through entropy, energy is required for a living system to exist. The main source of energy on Earth is the sun, but other sources of energy exist for life on Earth, such as hydrogen gas or methane, used in chemosynthesis.
The definition of life has long been a challenge for scientists and philosophers. [ 2 ] [ 3 ] [ 4 ] This is partially because life is a process, not a substance. [ 5 ] [ 6 ] [ 7 ] This is complicated by a lack of knowledge of the characteristics of living entities, if any, that may have developed outside Earth.
As Harold J. Morowitz (1992) explains it, life is a property of an ecological system rather than a single organism or species. [16] He argues that an ecosystemic definition of life is preferable to a strictly biochemical or physical one.
Matter organizes into various phases or states of matter depending on its constituents and external factors like pressure and temperature.Except at extreme temperatures and pressures, atoms form the three classical states of matter: solid, liquid and gas.
The biological organisation of life is a fundamental premise for numerous areas of scientific research, particularly in the medical sciences. Without this necessary degree of organisation, it would be much more difficult—and likely impossible—to apply the study of the effects of various physical and chemical phenomena to diseases and ...
Chemistry education (or chemical education) is the study of teaching and learning chemistry. It is one subset of STEM education or discipline-based education research (DBER). [ 1 ] Topics in chemistry education include understanding how students learn chemistry and determining the most efficient methods to teach chemistry.