【单选题】Which electrons are used to create images where contrast is proportional to average atomic number?
B.
Backscattered electrons
【单选题】At very low temperatures, superconductivity in a metal occurs where______.
A.
electrons do not move freely through the metal
B.
electrons are crowded together
C.
paired electrons move uninterruptedly
D.
paired electron dance together to and fro
【单选题】对于患有一般性心理问题的人而言,其不良情绪的反映程度表现为以下哪种?
【多选题】原油储罐(金属罐)发生沸溢和喷溅的典型征兆是( )。
A.
罐壁会剧烈抖动,伴有强烈的噪声(液体剧烈沸腾和金属罐壁变形所引起的)。
D.
油罐火灾一旦出现沸溢和喷溅的先兆,消防人员和器材必须撤到安全地带,以防造成更大损伤。
【简答题】It is not scientific for a normally inactive person to start a program of ( 剧烈的;强烈的 ) exercise suddenly.
【多选题】What is the source of the high-energy electrons used for ATP production?
A.
The source of the high-energy electrons that power the proton pumping differs widely between different organisms and different processes.
B.
During cell respiration—the energy-generating process that takes place in both mitochondria and aerobic bacteria—these electrons are ultimately derived from sugars or fats.
C.
In photosynthesis, the high-energy electrons come from the organic green pigment chlorophyll, which captures energy from sunlight.
D.
And many single-celled organisms (archaea and bacteria) use inorganic substances such as hydrogen, iron, and sulfur as the source of the high-energy electrons that they need to make ATP.
【单选题】Suppose that, in each trial, either electrons or protons had been added to each sphere to produce its charge. In Trial 3, which of the 2 types of particles would have been added to Sphere X, and which...
【简答题】The electrons that participate in chemical bonds are the valence electrons, which are the electrons found in an atom's outermost shell.
【简答题】The required number of electrons in noble gases’ outer shell is