解析 A。“Atom”在科学中意为“原子”,是构成物质的非常小的粒子;B 选项“a large object in space”指“太空中的大物体”;C 选项“a form of energy”是“一种能量形式”;D 选项“a type of wave”是“一种波”。因此选 A。 反馈 收藏
An atom is the smallest possible amount of a chemical element—so an atom of gold is the smallest amount of gold you can possibly have. By small, I really do mean absolutely, nanoscopically tiny: a single atom is hundreds of thousands of times thinner than a human hair, so you have ...
But matter is not spread evenly throughout the universe. We know this because we see it concentrated within galaxies and absent in the gaps between galaxies. However, when we talk about the density of matter in the universe, we're imagining spreading every atom in the universe (three-...
This latter is a naturally abundant organic coordination molecule with the chemical structure of C6H18O24P6 in which each phosphate group, characterizing the molecule, is connected to a carbon atom of the cyclo-hexamehexol ring [95]. Thanks to its non-toxicity, biocompatibility and environmental...
Presented at the fifteenth annual meeting of the National Science Teachers Association, 1966 in New York City, and reprinted from The Physics Teacher Vol. 7, issue 6, 1969, pp. 313-320 by permission of the editor and the author. I thank Mr. DeRose for th
Whereas, in science, an element is a substance entirely made of one type of atom. 10 The essence of a concept or thing often remains abstract and philosophical, focusing on underlying qualities. Elements are more concrete, representing tangible or specific parts that can be isolated and defined...
The SPACE (Strategic Position and Action Evaluation) analysis was developed by strategy academics Alan Rowe, Richard Mason, Karl Dickel, Richard Mann, and Robert Mockler. The particular focus of this framework is strategy formation as it relates to the c
As small as a nanometer is, it's still large compared to the atomic scale. An atom has a diameter of about 0.1 nm. An atom's nucleus is much smaller -- about 0.00001 nm. Atoms are the building blocks for all matter in our universe. You and everything around you are made of atoms...
an approximation of pi to 39 digits will suffice for any cosmological calculation humans might attempt. At that level of precision, which mathematicians achieved in 1630, you can calculate the circumference of the observableuniversewith an errorsmaller than the diameter of a single atom of hydrogen...
TwentyThousandLeaguesUnderTheSeaAbovemewasthecalmsurfaceofthesea.Wewerewalkingonfine,evensand,notwrinkled,asonaflatshore,whichkeepstheimpressionofthewaves.Thisdazzlingcarpet,reallyareflector,droveawaytheraysofthesunwithwonderfulintensity,whichaccountedforthevibrationwhichpassedthrougheveryatomofliquid. ...