We can distinguish three different realms of matter, three levels on the quantum ladder. The first is the atomic realm, which includes the world of atoms, their interactions, and the structures that are formed by them, such as molecules, liquids and solids, and gases and plasmas. This realm includes all the phenomena of atomic physics, chemistry, and, in a certain sense, biology. The energy exchanges taking place in this realm are of a relatively low order. If these exchanges are below one electron volt, such as in the collisions between molecules of the air in a room, then atoms and molecules can be regarded as elementary particles. That is, they have “conditional elementarity” because they keep their identity and do not change in any collisions or in other processes at these low energy exchanges. If one goes to higher energy exchanges, say 104 electron volts, then atoms and molecules will decompose into nuclei and electrons; at this level, the latter particles must be considered as elementary. We find examples of structures and processes of this first rung of the quantum ladder on Earth, on planets, and on the surfaces of stars.
The next rung is the nuclear realm. Here the energy exchanges are much higher, on the order of millions of electron volts. As long as we are dealing with phenomena in the atomic realm, such amounts of energy are unavailable, and most nuclei are inert: they do not change. However, if one applies energies of millions of electron volts, nuclear reactions, fission and fusion, and the processes of radioactivity occur; our elementary particles then are protons, neutrons, and electrons. In addition, nuclear processes produce neutrinos, particles that have no detectable mass or charge. In the universe, energies at this level are available in the centers of stars and in star explosions. Indeed, the energy radiated by the stars is produced by nuclear reactions. The natural radioactivity we find on Earth is the long-lived remnant of the time when now-earthly matter was expelled into space by a major stellar explosion.
The third rung of the quantum ladder is the subnuclear realm. Here we are dealing with energy exchanges of many billions of electron volts. We encounter excited nucleons, new types of particles such as mesons, heavy electrons, quarks, and gluons, and also antimatter in large quantities. The gluons are the quanta, or smallest units, of the force(the strong force)that keeps the quarks together. As long as we are dealing with the atomic or nuclear realm, these new types of particles do not occur and the nucleons remain inert. But at subnuclear energy levels, the nucleons and mesons appear to be composed of quarks, so that the quarks and gluons figure as elementary particles.
1. The primary topic of the passage is( ).
2. According to the passage, radioactivity that occurs naturally on Earth is the result of( ).
3. According to the passage, which of the following can be found in the atomic realm?
4. According to the author, gluons are not( ).
5. The passage speaks of particles as having conditional elementarity if they( ).
问题1选项
A.the interaction of the realms on the quantum ladder
B.atomic structures found on Earth, on other planets, and on the surfaces of stars
C.levels of energy that are released in nuclear reactions on Earth and in stars
D.particles and processes found in the atomic, nuclear, and subnuclear realms
问题2选项
A.the production of particles that have no detectable mass or electric charge
B.high energy exchanges on the nuclear level that occurred in an ancient explosion in a star
C.processes that occur in the center of the Sun, which emits radiation to the Earth
D.high-voltage discharges of electricity that took place in the atmosphere of the Earth shortly after the Earth was formed
问题3选项
A.More than one level of energy exchange
B.Exactly one elementary particle
C.Exactly three kinds of atomic structures
D.No particles smaller than atoms
问题4选项
A.found to be conditionally elementary
B.produced in nuclear reactions
C.encountered in subnuclear energy exchanges
D.related to the strong force
问题5选项
A.remain unchanged at the given level of energy exchange
B.cannot be decomposed into smaller constituents
C.release energy at a low level in collisions
D.belong to the nuclear level on the quantum ladder
第1题:D
第2题:B
第3题:A
第4题:B
第5题:A
1.主旨大意题。本篇开头介绍了我们可以区分物质的三个不同领域,在量子阶梯上的三个层次。接着三段分别阐述了原子能领域,原子核领域以及亚核领域的物质及物质产生过程。故D项“在原子、原子核和亚核领域中发现的粒子和过程”符合题意。
2.细节事实题。根据题干定位到第二段"However, if one applies energies of millions of electron volts, nuclear reactions, fission and fusion, and the processes of radioactivity occur; our elementary particles then are protons, neutrons, and electrons." 然而,如果一个人应用数百万电子伏特的能量,核反应、裂变和聚变,那么放射性过程就会发生;我们的基本粒子是质子、中子和电子。据此可知地球上自然发生的放射性现象是极高的能量交换发生反应的结果。故B项“是一个古老的恒星爆炸过程中的高能量的核水平交换的结果”正确。
3.细节事实题。由题干关键词“atomic realm”可定位到第一段If these exchanges are below one electron volt, ……If one goes to higher energy exchanges, say 104 electron volts, then atoms and molecules will decompose into nuclei and electrons; at this level, the latter particles must be considered as elementary. 如果这些交换低于1电子伏特,如果进行更高的能量交换,比如104电子伏特,那么原子和分子就会分解成原子核和电子;在这个层次上,后一种粒子必须被认为是基本粒子。据此可知第一段在原子领域不止一级能量交换,可以有高能量和低能量交换。故A项正确。B项与原文内容"then atoms and molecules will decompose into nuclei and electrons; at this level, the latter particles must be considered as elementary. " 那么原子和分子就会分解成原子核和电子;在这个。层次上,后一种粒子必须被认为是基本粒子”不符,原子领域除了基本粒子还有其他成分。CD两项第一段未提及。
4.细节事实题。由题干关键词gluons定位到第三段"The gluons are the quanta, or smallest units, of the force(the strong force)that keeps the quarks together. As long as we are dealing with the atomic or nuclear realm, these new types of particles do not occur and the nucleons remain inert. But at subnuclear energy levels, the nucleons and mesons appear to be composed of quarks, so that the quarks and gluons figure as elementary particles." 胶子是使夸克聚集在一起的力(强力)的量子,或最小的单位。只要我们研究的是原子或核领域,这些新型粒子就不会出现,核子也会保持惰性。但是在亚核能级,核子和介子似乎是由夸克组成的,所以夸克和胶子是基本粒子。据此可知胶子不会出现在原子和核领域,故B项正确。其他选项与题干中的gluons无关。
5.细节事实题。由题干关键词"conditional elementarity"定位到第一段" If these exchanges are below one electron volt, such as in the collisions between molecules of the air in a room, then atoms and molecules can be regarded as elementary particles. That is, they have “conditional elementarity” because they keep their identity and do not change in any collisions or in other processes at these low energy exchanges. " 如果这些交换低于1电子伏特,例如在一个房间里空气分子之间的碰撞,那么原子和分子可以被视为基本粒子。也就是说,它们有“条件元素性”因为它们保持它们的同一性,在任何碰撞或其他低能量交换过程中都不会改变。据此可知条件元素性在能量交换过程中不会改变。故A项“给定的能量交换水平上保持不变”正确。