Chemistry
The Earths Atmosphere
The Earth's atmosphere is a layer of gases that surrounds the planet, providing the air we breathe and playing a crucial role in regulating temperature and protecting life from harmful solar radiation. It is composed mainly of nitrogen and oxygen, with trace amounts of other gases such as carbon dioxide and water vapor. The atmosphere is divided into distinct layers based on temperature variations.
Written by Perlego with AI-assistance
Related key terms
1 of 5
10 Key excerpts on "The Earths Atmosphere"
eBook - PDF- Amrita Pandey(Author)
- 2019(Publication Date)
- Delve Publishing(Publisher)
Atmosphere: A Component of Earth Ecosystem 3 CONTENTS 3.1. Introduction ...................................................................................... 46 3.2. Features And Significance Of The Atmosphere .................................. 48 3.3. Layers of the Atmosphere .................................................................. 49 3.4. Chemical Composition Of The Atmosphere ...................................... 51 3.5. Permanent And Variable Gases ......................................................... 54 3.6. Elements Of The Atmosphere ............................................................ 56 3.7. Major Atmospheric Environmental Concerns .................................... 64 References ............................................................................................... 68 Earth Systems and Environment 46 The atmosphere is a system, which aids in the regulation of climate of the earth. It also helps in the distribution of heat all around the globe. The at-mosphere of the earth is a thin covering comprised of gases surrounding the solid planet, the biosphere, and the hydrosphere. The key compositions of the atmosphere mainly contains nitrogen and oxygen. It contains certain chemicals also that absorb heat from the surface of the earth radiate it in every direction. The chapter basically deals with the fundamental concept of atmosphere, its features and significance. Later, different layers of the atmosphere have been described along with the chemical composition of the atmosphere. A brief introduction to the permanent and variable gases has also been explained in brief. A short description of major elements of the atmosphere are also discussed. Towards the end of this chapter, two major atmospheric environmental concerns have also been described. 3.1. INTRODUCTION The atmosphere of the earth is a critical system for life on the planet.
eBook - ePub- Ann M Holloway, Richard P Wayne(Authors)
- 2015(Publication Date)
- Royal Society of Chemistry(Publisher)
CHAPTER 1 Earth’s Atmosphere1.1 CHEMISTRY IN THE ATMOSPHERE
Our atmosphere is an extraordinary mixture of gases and suspended particles, some inert and some highly reactive, some present in large quantities while others are found only in the minutest traces. New material is being added continuously to the atmosphere at the surface boundary, with materials trapped within the Earth, perhaps when the planet was formed, being liberated, sometimes slowly and gently, and sometimes violently in volcanic eruptions. So far, this description would also fit the atmospheres of our near neighbours Venus and Mars. But on Earth, the living organisms (the biota ) make a quite dramatic contribution of their own to the supply of chemicals to the atmosphere. Humans are part of the biota, and are making an impact on the atmosphere out of all proportion to human life’s biological importance, as we shall see time and again in this book. The study of the chemistry of the ‘natural’ atmosphere is truly fascinating in its own right. But it is also clear that the chemist who has a good understanding of how this natural atmosphere works is one of the most likely candidates to make rational and informed suggestions about ways to offset Man’s depredations. Policy makers (and politicians) need chemists!The mixture of gases and particles naturally contains many substances that can react with others that are present, and one of the primary tasks of the atmospheric chemist is to interpret the composition of atmosphere in terms of the pathways and rates of the reactions that occur. A knowledge, preferably obtained from experimental observations, of the possible mechanisms and of the chemical kinetics
eBook - PDFFundamentals of Environmental and Toxicological Chemistry
Sustainable Science, Fourth Edition
- Stanley E. Manahan(Author)
- 2013(Publication Date)
- CRC Press(Publisher)
155 6 Environmental and Toxicological Chemistry of the Atmosphere 6.1 ATMOSPHERE: AIR TO BREATHE AND MUCH MORE We live and breathe in the atmosphere, a sea of gas composed mostly of elemental nitrogen gas (N 2 ), O 2 , and water vapor. The fundamental properties of gases determine the properties of the atmosphere. Recall that gases consist of molecules and (in the case of noble gases) atoms with large amounts of space between them. The gas molecules are in constant, rapid motion, which causes gases to exert pressure . The motion of gas molecules becomes more rapid with increasing temperature . Due to their constant motion, gas molecules move by a process called diffusion . The relationships among the amount of a gas in moles and its volume, temperature, and pressure can be calculated by the gas laws discussed in Chapter 19. Figure 6.1 shows some of the main features and aspects of the atmosphere and its relationship to other environmental spheres. Having a total mass of about 5.15 × 10 15 t (only about one-millionth of Earth’s total mass), the atmosphere is a layer of gases blanketing Earth, whose density diminishes rapidly with increasing altitude. More than 99% of the atmosphere’s mass is within 40 km of Earth’s surface, with the majority of the air lying below a 10 km altitude (compared to Earth’s diameter of almost 13,000 km). A person exposed to air at the approximately 13,000 m altitude at which com-mercial jet aircrafts fly can remain conscious for only about 15 seconds without supplementary oxygen. There is no clearly defined upper limit to the atmosphere, which keeps getting thinner with increasing altitude. A practical upper limit may be considered to be an altitude of about 1000 km, above which air molecules can be lost to space (a region called the exosphere ). If Earth were the size of a classroom globe, virtually all the mass of the atmosphere would be contained in a layer the thickness of the coat of varnish on the globe.
No longer available |Learn more- (Author)
- 2014(Publication Date)
- Learning Press(Publisher)
It is a multidisciplinary field of research and draws on environmental chemistry, physics, meteorology, computer modeling, oceanography, geology and volcanology and other disciplines. Research is increasingly connected with other areas of study such as climatology. The composition and chemistry of the atmosphere is of importance for several reasons, but primarily because of the interactions between the atmosphere and living organisms. The composition of the Earth's atmosphere has been changed by human activity and some of these changes are harmful to human health, crops and ecosystems. Examples of problems which have ______________________________ WORLD TECHNOLOGIES ______________________________ been addressed by atmospheric chemistry include acid rain, ozone depletion, photochemical smog and global warming. Atmospheric chemistry seeks to understand the causes of these problems, and by obtaining a theoretical understanding of them, allow possible solutions to be tested and the effects of changes in government policy evaluated. Atmospheric composition Average composition of dry atmosphere, by volume Gas per NASA Nitrogen, N 2 78.084% Oxygen, O 2 20.946% Argon, Ar 0.934% Minor constituents (in ppm) Carbon Dioxide, CO 2 383 Neon, Ne 18.18 Helium, He 5.24 Methane, CH 4 1.7 Krypton, Kr 1.14 Hydrogen, H 2 0.55 Water Water vapour Highly variable; typically makes up about 1% Notes: the concentration of CO 2 and CH 4 vary by season and location. The mean molecular mass of air is 28.97 g/mol. History The ancient Greeks regarded air as one of the four elements, but the first scientific studies of atmospheric composition began in the 18th century. Chemists such as Joseph Priestley, Antoine Lavoisier and Henry Cavendish made the first measurements of the composition of the atmosphere.
eBook - PDFThe Atmospheric Environment
Effects of Human Activity
- Michael B. Mcelroy(Author)
- 2021(Publication Date)
- Princeton University Press(Publisher)
Atmospheric History and Composition While there are scores of detectable chemical species in the atmosphere, the number of elements represented by these compounds is surprisingly limited. Nitrogen, oxygen, carbon, hydrogen, and the noble gas argon (Ar) account for all but a few parts in one hundred thousand of the at- mosphere. If we add the noble gases neon, helium, krypton, and xenon, we can accommodate all but one part in one billion. As we shall see, the atmosphere’s chemical complexity is largely a consequence of the influ- ence of life; to explain the comparative simplicity of the atmosphere’s el- emental composition, we need to examine the processes that led to the origin of the atmosphere in the first place. We begin in Section 5.1 with a description of the processes that led to the formation of Earth from the primitive solar nebula. The importance of life for the early evolution of the atmosphere is discussed in Section 5.2. Perspectives on the recent changes in atmospheric composition are devel- oped in Section 5.3. A particular objective in Section 5.3 is to provide a context within which to assess the significance of contemporary changes in atmospheric composition arising as results of various forms of human activity. Summary remarks are presented in Section 5.4. 5.1 Perspectives on the Origin and Early Evolution of Earth as a Planet Our story begins almost five billion years ago with the formation of the solar system from a spinning nebula of gas and dust. Initially, the nebula was hot. As time elapsed, the nebula cooled, mainly by loss of heat through radiation (emission of light) from its edges. Gases near the cen- ter of the nebula collected to form the Sun. Materials condensing else- where eventually assembled to form the diverse suite of planets, satellites, rings, meteorites, and comets characterizing our solar system today. The cooling sequence resulted in segregation of condensable materials with time and position in the nebula.
eBook - PDF- Bruce Anderson, Alan H. Strahler(Authors)
- 2012(Publication Date)
- Wiley(Publisher)
The Earth’s Atmosphere 28 2 As Philippine farmers plow their fields, Mount Pinatubo erupts on July 8, 1991. CHAPTER OUTLINE Altitude, km 2 1 1.5 Treeline ■ Composition of the Atmosphere p. 30 ■ Temperature Structure of the Atmosphere p. 39 ■ Atmospheric Pressure and Density p. 43 The atmosphere Figure 2.1 The Earth’s atmosphere, shown here in profile, is a thin layer sur- rounding our planet. The lower layer of clouds and weather is called the troposphere. Composition of the Atmosphere he Earth is surrounded by an envelope of air—a mixture of various gases—that makes up our atmosphere (Figure 2.1). This envelope of air, held in place by the Earth’s gravity, reaches a height of hundreds of kilometers. However, about 97 percent of the atmo- sphere lies within 30 km (19 mi) of the Earth’s surface, which is the focus of most of our discussions in this text. In these lower regions, pure, dry air is mostly made up of nitrogen (about 78 percent by volume) and oxy- gen (about 21 percent), as seen in Figure 2.2. The remaining 1 percent of dry air is mostly argon, with a Describe the gases that make up the atmosphere. Explain the vital role of ozone for life on the Earth. Explain what aerosols are and why they are important. LEARNING OBJECTIVES very small amount of carbon dioxide (CO 2 ), amount- ing to about 0.035 percent. In the real atmosphere, we also have to account for gaseous water vapor, which can be between 0.5–2.0 percent of the atmosphere by vol- ume. Here we examine the role some of these gases play in the atmosphere. RADIATIVELY AND CHEMICALLY INACTIVE GASES Nitrogen molecules in the atmosphere contain two ni- trogen atoms (N 2 ). Nitrogen gas does not easily react with other substances, so we can think of it as a mainly neutral substance. Soil bacteria do extract very small amounts of nitrogen, which can be used by plants, but otherwise nitrogen is largely a “filler,” adding inert bulk to the atmosphere.
No longer available |Learn more- (Author)
- 2014(Publication Date)
- The English Press(Publisher)
________________________ WORLD TECHNOLOGIES ________________________ Chapter- 5 Atmosphere of Earth Blue light is scattered more than other wavelengths by the gases in the atmosphere, giving the Earth a blue halo when seen from space. ________________________ WORLD TECHNOLOGIES ________________________ Limb view, of the Earth's atmosphere. Colours roughly denote the layers of the atmosphere. The atmosphere of Earth is a layer of gases surrounding the planet Earth that is retained by Earth's gravity. The atmosphere protects life on Earth by absorbing ultraviolet solar radiation, warming the surface through heat retention (greenhouse effect) and reducing temperature extremes between day and night. Atmospheric stratification describes the structure of the atmosphere, dividing it into distinct layers, each with specific characteristics such as temperature or composition. The atmosphere has a mass of about 5×10 18 kg, three quarters of which is within about 11 km (6.8 mi; 36,000 ft) of the surface. The atmosphere becomes thinner and thinner with increasing altitude, with no definite boundary between the atmosphere and outer space. An altitude of 120 km (75 mi) is where atmospheric effects become noticeable during atmospheric reentry of spacecraft. The Kármán line, at 100 km (62 mi), also is often regarded as the boundary between atmosphere and outer space. Air is the name given to atmosphere used in breathing and photosynthesis. Dry air contains roughly (by volume) 78.09% nitrogen, 20.95% oxygen, 0.93% argon, 0.039% carbon dioxide and small amounts of other gases. Air also contains a variable amount of water vapor, on average around 1%. While air content and atmospheric pressure varies at different layers, air suitable for the survival of terrestrial plants and terrestrial animals is currently known only to be found in Earth's troposphere and artificial atmospheres.
eBook - PDF- R.A. Bailey(Author)
- 2012(Publication Date)
- Academic Press(Publisher)
44 CHEMISTRY OF THE ENVIRONMENT the same percentage composition, since the earth was formed? If not, what sorts of evolution have been hypothesized for the earth's atmosphere? (e) What variations exist in the earth's atmosphere as we go from the surface of the earth to the limits of the atmo-sphere? This question is closely related to the one about the earth's heat balance. (f) What do we know about the general circulation of the atmosphere? After all, carbon dioxide and dust particles are released into the atmosphere at particular locations on the earth's surface. How far do they spread through the atmosphere, both horizontally and vertically? (g) Although the carbon dioxide and dust particles released into the atmosphere by man's efforts are said to affect the total, or macroclimate of the earth, do not man's activities also affect the earth's microclimate? What do we know about the special climates of cities, as opposed to their surrounding countrysides? How do the pollutants produced by man's activities in cities become trapped in the atmosphere above these cities, to become hazards to man's health? These next two chapters will attempt to answer these questions, though not necessarily in the order in which they have been presented. The answers to some of these questions are complex and, in some cases, not particularly well understood. It will thus be seen that questions and answers concerning the atmosphere and man's effect on the atmosphere and climate are not simple and need a great deal of further study, preferably before irreparable harm is done. 3.2 GASEOUS CONSTITUENTS OF THE ATMOSPHERE Table 3-1 shows the constituents of clean, dry air near sea level. Usually, the atmosphere also contains water vapor and dust, but these occur in amounts that vary widely from place to place and from time to time.
eBook - PDF- E. Mészáros(Author)
- 1981(Publication Date)
- Elsevier Science(Publisher)
2. Formation and evolution of the Earth’s atmosphere. Chemistry of main constituents 21 Statement of the problem It can clearly be seen from Table 1 that the Earth’s atmosphere consists mainly of nitrogen and oxygen. However, this composition, which makes the present life on our planet possible, cannot be considered “normal” in the solar system. Thus, even the nearest planets like Mars and Venus have a very different atmospheric composition. The results ofspace research, especially the results obtained by the Soviet Venera and the American Mariner space-crafts, make it possible to estimate numerically these differences in the composition. Table 2 contains data on the global composition of the atmosphere of Venus, Earth and Mars according to Lovelock and Margulis (1974). The values given in the table are expressed in millibars partial pressure of the gas considered. It follows from the table that the pressure on the surface of Venus is high while it is low in the case of the Martian atmosphere. However, on both planets the atmosphere consists essentially of carbon dioxide, and oxygen is either missing or its pressure is very low. On the other hand, the Earth’s atmosphere is composed of nitrogen and oxygen and the quantity of CO, is virtually negligible. In the fourth column of the table are values obtained by interpolation on the basis of the astronomical data of the Earth (e.g. distance from the Sun) and of the composition of the atmospheres’ of Venus and Mars. This interpolated atmosphere is called the estimated equilibrium atmosphere (Lovelock and Margulis, 1974). One can see that the real CO, partial pressure is a thousand times smaller while the real 0, pressure is nearly a thousand times greater than these values obtained by interpolation between Mars and Venus. Another peculiarity of the Earth’s atmosphere is the relatively high nitrogen pressure.
eBook - PDF- P. D. Osborn(Author)
- 2016(Publication Date)
- Butterworth-Heinemann(Publisher)
There are wide variations in the thickness of the layer depending on topography and weather conditions and there are some exceptional forms of life which can survive above the Boundary layer. l 2 The atmosphere Finally it is useful to define some other prefixes of -sphere which are used: Lithosphère Rock and soil of Earth's surface Hydrosphere Seas and lakes Atmosphere The air close to the surface Biosphere The zone of life Ecosphere The field of ecology which is concerned with the balance of all the factors which have a bearing on the survival of life in all its forms. The word 'atmosphere' when used in this book without further definition has its common parlance meaning namely the part of the troposphere in which creatures can live and breathe. The chemistry of the upper layers is examined at A.3.1 because the reactions which are taking place there have a critical influence on our environment, but the rest of the book concerns itself with the boundary layer. A.l Some historical concepts of the atmosphere and its make up There have always been airborne contaminants but, until the industrial age and the concurrent explosion in human population, man's contribution was of no conse-quence compared with what were generally regarded as the infinite resources of the planet. Even since the industrial age and up to the first few decades of the twentieth century man's effect on the total environment remained small and localized. How-ever, as we approach the last decade of this century the rate of increase in pollution generally threatens most of the major population centres of the world. This book is not concerned with the emotional and political aspects of pollution and is confined to contamination of the atmosphere; this alone has spawned national and international research and monitoring programmes using technology and novel approaches unheard of a generation ago.
Index pages curate the most relevant extracts from our library of academic textbooks. They’ve been created using an in-house natural language model (NLM), each adding context and meaning to key research topics.
