Inconvenient Truth
These man caused factors on the environment makes our future work as physicians more complicated and challenging. I can't wait to discuss this with my teachers as to how they would account for human acts in our Tian Gan and Di Zhi cycles. I certainly hope that the heavens take pity on "us" and allow a way out of the mess.
2007年7月17日星期二
Semiconductor of the week
Germanium (Ge) is a elemental semiconductor. Its atomic number is 32 and has an atomic weight of 72.59 and has a melting point of 937.4 degrees celcius. The element is brittle rather than ductile; the atoms in its crystals are arranged as are the carbon atoms in diamond. It is oxidized at 600°–700° C (1,100°–1,300° F) and reacts quickly with the halogens to form tetrahalides. Germanium forms stable oxidation states of +2 and +4, the compounds of the latter being more stable and numerous. The two most important compounds of germanium are the dioxide (GeO2) and the tetrachloride (GeCl4). Germanates, formed by heating the dioxide with basic oxides, include zinc germanate (Zn2GeO4), used as a phosphor (a substance that emits light when energized by radiation). The tetrachloride, already mentioned as an intermediate in obtaining germanium from its natural sources, is a volatile, colourless liquid that freezes at about -50° C (-58° F) and boils at 84° C (183.2° F).
Welcome to Chembalancer
Ahh.... to relive high school chemistry problems. I remember enjoying these problems more as a 16 year old. Conservation of mass was such an eye opener; now it seems like old hat. Some basic algebraic knowledge helped me navigate these exercises.
Genearl Chemistry: Balancing Equations
I am ready to help my son in a year or two when he takes high school chemistry.
Germanium (Ge) is a elemental semiconductor. Its atomic number is 32 and has an atomic weight of 72.59 and has a melting point of 937.4 degrees celcius. The element is brittle rather than ductile; the atoms in its crystals are arranged as are the carbon atoms in diamond. It is oxidized at 600°–700° C (1,100°–1,300° F) and reacts quickly with the halogens to form tetrahalides. Germanium forms stable oxidation states of +2 and +4, the compounds of the latter being more stable and numerous. The two most important compounds of germanium are the dioxide (GeO2) and the tetrachloride (GeCl4). Germanates, formed by heating the dioxide with basic oxides, include zinc germanate (Zn2GeO4), used as a phosphor (a substance that emits light when energized by radiation). The tetrachloride, already mentioned as an intermediate in obtaining germanium from its natural sources, is a volatile, colourless liquid that freezes at about -50° C (-58° F) and boils at 84° C (183.2° F).
Welcome to Chembalancer
Ahh.... to relive high school chemistry problems. I remember enjoying these problems more as a 16 year old. Conservation of mass was such an eye opener; now it seems like old hat. Some basic algebraic knowledge helped me navigate these exercises.
Genearl Chemistry: Balancing Equations
I am ready to help my son in a year or two when he takes high school chemistry.
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