首页
登录
职称英语
【B1】 [br] 【B2】 [originaltext]A summary of the physical and chemical nature of li
【B1】 [br] 【B2】 [originaltext]A summary of the physical and chemical nature of li
游客
2024-03-04
51
管理
问题
【B1】 [br] 【B2】
A summary of the physical and chemical nature of life must begin, not on the Earth, but in the Sun. In fact, it is at the Sun’s very center. It is here that is to be found the source of the energy that the Sun constantly pours out into space as light and heat. This energy is liberated at the center of the Sun as billions upon billions of nuclei of hydrogen atoms collide with each other and fuse together to form nuclei of helium(氦). And, in doing so, it releases some of the energy that is stored in the nuclei of atoms. The output of light and heat of the Sun requires that some 600 million tons of hydrogen be converted into helium in the Sun every second. This the Sun has been doing for several thousands of millions of years.
The nuclear energy is released at the Sun’s center as high-energy gamma radiation, a form of electro-magnetic radiation like light and radio waves, only of very much shorter wavelength. This gamma radiation is absorbed by atoms inside the Sun, to be re-emitted at slightly longer wavelengths. This radiation, in its turn, is absorbed and re-emitted. As the energy filters through the layers of the solar interior, it passes through the X-ray part of the spectrum(频谱), eventually becoming light. At this stage, it has reached what we call: the solar surface and can escape into space, without being absorbed further by solar atoms. A very small fraction of the Sun’s light and heat is emitted in such directions that after passing through space, it hits the Earth.
选项
答案
Constantly
解析
转载请注明原文地址:https://tihaiku.com/zcyy/3503360.html
相关试题推荐
[originaltext]W:Jason,actuallyI’mgoingtoEnglandthissummer.M:Really?
[originaltext]I’dliketolookatavitalaspectofe-commerce,andthatis
[originaltext]I’dliketolookatavitalaspectofe-commerce,andthatis
[originaltext]Moderator:Hello,ladiesandgentlemen.Itgivesmegreat
[originaltext]Moderator:Hello,ladiesandgentlemen.Itgivesmegreat
[originaltext]Moderator:Hello,ladiesandgentlemen.Itgivesmegreat
[originaltext]Moderator:Hello,ladiesandgentlemen.Itgivesmegreat
[originaltext]Passwordsareimportant.Youremployer,yourbankandyoursm
[originaltext]Passwordsareimportant.Youremployer,yourbankandyoursm
[originaltext]Whenitcomestosuccessintheschoolenvironment,whatare
随机试题
Toimpressafutureemployer,oneshoulddressneatlyandbe______.A、swiftB、ins
AntIntelligenceA)Whenwethinkofintelligentmemb
TheCommunicativeApproachTheCommunicativeApproachemphasizesthatthegoal
有防冻要求的混凝土宜选用的水泥是()。A.矿渣水泥 B.普通水泥 C.
子宫颈原位癌的治疗选择是A.广泛子宫切除术及双侧盆腔淋巴结清除术 B.全子宫切
医德实践的具体内容不包括()A.医德规范体系 B.医德评价 C.医德
《变电评价管理规定第27分册土建设施精益化评价细则》:要求电容器室应设置采光玻璃
幼儿园放学时,萌萌的父亲临时有事,便委托其同事王某到园接萌萌。张老师在与萌萌的父
(2016年11月)培训评估属于()中的内容。A.培训管理体系 B.培训课程体
观察学习的基本过程有哪些
最新回复
(
0
)