Essentials of environmental science friedland pdf download

Essentials of Environmental Science is ideal for a one-semester course. It takes the same non-biased approach as its parent text, teaching students to think critically about data presented. In addition to being briefer, Essentials is even more accessible placing less emphasize on math calculations. The coverage of ecology, agriculture, energy, and water has also been streamlined to provide a more focused treatment of the science concepts.

International system of units Metric system --and common U. Topics covered in 'Essentials Of Environmental Science' include: cellular basis of life, ecosystems, natural resources, water pollution, soil pollution, noise pollution, solid waste management, human population growth and health, and global issues on environment. This revised fifth edition, is a lucid presentation of the fundamental concepts and principles of ecology and environmental science.

Extensively illustrated, the book provides in-depth coverage of major areas such as atmospheric and soil science, hydrobiology, biodiversity, and pollution ecology. It seeks to impart comprehensive understanding of the major ecological issues, policies and laws, crucial for solving environmental problems. New sections on vital topics such as acid rain and deposition, metapopulations, environmental disasters and the Bali Summit on Climate Change contribute strongly to this endeavour.

A large system may contain many smaller systems within it. In this case, the fish and its internal organs are the system being studied. In the same environment, a marine biologist might study the predator-prey relationship between cod and herring. That relationship constitutes another system, which includes two fish species and the environment they live in.

A fisheries management official might study a system that includes all of the systems above as well as people, fishing technology, policy, and law. The largest system that environmental science considers is Earth. Many of our most important current environmental issues—including human population growth and climate change—exist at the global scale. Throughout this book we will define a given system in terms of the environmental issue we are studying and the scale in which we are interested.

Whether we are investigating ways to reduce pollution, increase food supplies, or find alternatives to fossil fuels, environmental scientists must have a thorough understanding of matter and energy and their interactions within and across systems. We will begin this chapter by exploring the properties of matter. We will then discuss the various types of energy and how they influence and limit systems.

Name some examples. What are some examples of smaller systems within that system? To a physiologist, a cod is a system. Cod Herring To a marine biologist, the predator-prey relationship between two fish species forms a system.

For an oceanographer, the system might consist of ocean currents and their effects on fish populations. Current A fisheries manager is interested in a larger system, consisting of fish populations as well as human activities and laws. Physiologists, marine biologists, oceanographers, and fisheries managers would describe the North Atlantic Ocean fisheries system differently. All environmental systems consist of matter What do rocks, water, air, the book in your hands, and the cells in your body have in common?

They are all forms of matter. Matter is anything that occupies space and has mass. The mass of an object is defined as a measure of the amount of matter it contains. Note that the words mass and weight are often used interchangeably, but they are not the same thing. Weight is the force that results from the action of gravity on mass. Whatever your weight is on Earth, you would have a lesser weight on the Moon, where the action of gravity is less. In contrast, mass stays the same no matter what gravitational influence is acting on an object.

So although your weight would change on the Moon, your mass would remain the same because the amount of matter you are made of would be the same. Atoms and Molecules All matter is composed of tiny particles that cannot be broken down into smaller pieces.

The basic building blocks of matter are known as atoms. An atom is the smallest particle that can contain the chemical properties of an element.

An element is a substance composed of atoms that cannot be broken down into smaller, simpler components. Atoms are so small that a single human hair measures about a few hundred thousand carbon atoms across.

Ninety-four elements occur naturally on Earth, and another 24 have been produced in laboratories. The periodic table lists all of the elements currently known. For a copy of the periodic table, turn to the inside back cover of this book. Each element is identified by a oneor two-letter symbol; for example, the symbol for carbon is C, and the symbol for oxygen is O.

These symbols are used to describe the atomic makeup of molecules, which are particles containing more than one atom. Molecules that contain more than one element are called compounds. For example, a carbon dioxide molecule CO2 is a compound composed of one carbon atom C and two oxygen atoms O2.

Protons and neutrons have roughly the same mass— both minutely small. The number of protons in the nucleus of a particular element—called the atomic number—is unique to that element. Neutrons have no electrical charge, but they are critical to the stability of nuclei because they keep the positively charged protons together. Without them, the protons would repel one another and separate.

In this space, electrons exist in orbitals, which are electron clouds that extend different distances from the nucleus. All carbon isotopes behave the same chemically. However, biological processes sometimes favor one isotope over another. These signatures allow environmental scientists to learn about certain processes by determining the proportions of different isotopes in soil, air, water, or ice. An atom is composed of protons, neutrons, and electrons.

Neutrons and positively charged protons make up the nucleus. Negatively charged electrons surround the nucleus. In the molecular world, opposites always attract, so negatively charged electrons are attracted to positively charged protons. This attraction binds the electrons to the nucleus. In a neutral atom, the numbers of protons and electrons are equal.

In any electron orbital, there can be only a certain number of electrons. The total number of protons and neutrons in an element is known as its mass number. Because the mass of an electron is insignificant compared with the mass of a proton or neutron, we do not include electrons in mass number calculations.

Although the number of protons in a chemical element is constant, atoms of the same element may have different numbers of neutrons, and therefore different mass numbers.

These various kinds of atoms are called isotopes. Isotopes of the element carbon, for example, all have six protons, but can occur with six, seven, or eight neutrons, yielding mass numbers of 12, 13, or 14, respectively. Unstable isotopes are radioactive.

Radioactive isotopes undergo radioactive decay, the spontaneous release of material from the nucleus. Radioactive decay changes the radioactive element into a different element. For example, uranium U decays to form thorium Th. The original atom uranium is called the parent and the resulting decay product thorium is called the daughter.

The radioactive decay of U and certain other elements emits a great deal of energy that can be captured as heat. Nuclear power plants use this heat to produce steam that turns turbines to generate electricity. We measure radioactive decay by recording the average rate of decay of a quantity of a radioactive element. Knowledge of the half-life allows scientists to determine the length of time that a particular radioactive element may be dangerous.

For example, using the half-life allows scientists to calculate the period of time that people and the environment must be protected from depleted nuclear fuel, like that generated by a nuclear power plant. As it turns out, many of the elements produced during the decay of U have half-lives of tens of thousands of years and more.

From this we can see why long-term storage of radioactive nuclear waste is so important. The measurement of isotopes has many applications in environmental science as well as in other scientific fields. For example, carbon in the atmosphere exists in a known ratio of the isotopes carbon 99 percent , carbon 1 percent , and carbon which occurs in trace amounts, on the order of one part per trillion.

Carbon is radioactive and has a half-life of 5, years. Carbon and carbon are stable isotopes. Living organisms incorporate carbon into their tissues at roughly the known atmospheric ratio.

But after an organism dies, it stops incorporating new carbon into its tissues. Over time, the radioactive carbon in the organism decays to nitrogen By calculating the proportion of carbon in dead biological material—a technique called carbon dating—researchers can determine how many years ago an organism died.

The single electron in the outer shell of the sodium atom is transferred to the vacant position in the outer shell of the chlorine atom. Chemical Bonds We have seen that matter is composed of atoms, which form molecules or compounds. In order to form molecules or compounds, atoms must be able to interact or join together. This happens by means of chemical bonds of various types. Chemical bonds fall into three categories: covalent bonds, ionic bonds, and hydrogen bonds.

These compounds are said to be held together by covalent bonds. A methane molecule is made up of one carbon C atom surrounded by four hydrogen H atoms. Covalent bonds form between the single carbon atom and each hydrogen atom. Covalent bonds also hold the two hydrogen atoms and the oxygen atom in a water molecule together. Another kind of bond between two atoms involves the transfer of electrons.

When such a transfer happens, one atom becomes electron deficient positively charged , and the other becomes electron rich negatively charged. This charge imbalance holds the two atoms together. The charged atoms are called ions, and the attraction between oppositely charged ions forms a chemical bond called an ionic bond.

Sodium Na donates one electron to chlorine Cl , which gains one electron, to form sodium chloride NaCl , or table salt. Molecules such as methane CH4 are associations of atoms held together by covalent bonds, in which electrons are shared between the atoms.

As a result of the four hydrogen atoms sharing electrons with a carbon atom, each atom has a complete set of electrons in its outer shell—two for the hydrogen atoms and eight for the carbon atom. A sodium atom and a chlorine atom can readily form an ionic bond. The sodium atom loses an electron, and the chlorine atom gains one.

The attraction between the oppositely charged ions—an ionic bond—forms sodium chloride NaCl , or table salt. An ionic bond is not usually as strong as a covalent bond. This means that the compound can readily dissolve. As long as sodium chloride remains in a salt shaker, it remains in solid form. A hydrogen bond is a weak chemical bond that forms when hydrogen atoms that are covalently bonded to one atom are attracted to another atom on another molecule.

When atoms of different elements form bonds, their electrons may be shared unequally; that is, shared electrons may be pulled closer to one atom than to the other. In some cases, the strong attraction of the hydrogen electron to other atoms creates a charge imbalance within the covalently bonded molecule. Among these properties are surface tension, capillary action, a high boiling point, and the ability to dissolve many different substances—all essential to physiological functioning.

Water is a polar molecule because its shared electrons spend more time near the oxygen atom than near the hydrogen atoms. The hydrogen atoms thus have a slightly positive charge, and the oxygen atom has a slightly negative charge. The result is a hydrogen bond between the two molecules. The ability to cohere or adhere underlies two unusual properties of water: surface tension and capillary action.

Have you ever seen an aquatic insect, such as a water strider, walk across the surface of the water? Surface tension also makes water droplets smooth and more or less spherical as they cling to a water faucet before dropping. Capillary action happens when adhesion of water molecules to a surface is stronger than cohesion between the molecules.

The absorption of water by a paper towel or a sponge is the result of capillary action. This property is important in thin tubes, such as the waterconducting vessels in tree trunks, and in small pores in soil. It is also important in the transport of underground water, as well as dissolved pollutants, from one location to another. Each water molecule as a whole is neutral; that is, it carries neither a positive nor a negative charge.

But water has unequal covalent bonds between its two hydrogen atoms and one oxygen atom. Because of these unequal bonds and the angle formed by the H-O-H bonds, water is known as a polar molecule. In a polar molecule, one side is more positive and the other side is more negative.

That attraction forms a hydrogen bond between the two molecules. By allowing water molecules to link together, hydrogen bonding gives water a number of unusual properties. Hydrogen bonds also occur in nucleic acids such as DNA, the biological molecule that carries the genetic code for all organisms.

Hydrogen bonding between water molecules creates the surface tension necessary to support this water strider. Where else in nature can you witness surface tension? With its molecules farther apart, solid water ice is less dense than liquid water. This property allows ice to float on liquid water. In addition, the hydrogen bonding between water molecules means that it takes a great deal of energy to change the temperature of water.

Thus the water in organisms protects them from wide temperature swings. Hydrogen bonding also explains why geographic areas near large lakes or oceans have moderate climates. The water body holds summer heat, slowly releasing it as the atmosphere cools in the fall, and warms only slowly in spring, thereby preventing the adjacent land area from heating up quickly. Water has another unique property: it takes up a larger volume in solid form than it does in liquid form.

You can see the result any time you add an ice cube to a drink: ice floats on liquid water. What does this unique property of water mean for life on Earth?

Imagine what would happen if water acted like most other liquids. As it cooled, it would continue to become denser. Its solid form ice would sink, and lakes and ponds would freeze from the bottom up. As a result, very few aquatic organisms could survive in temperate and cold climates.

Many substances, such as table salt, dissolve well in water because their polar molecules bond easily with other polar molecules. This explains the high concentrations of dissolved ions in seawater as well as the capacity of living organisms to store many types of molecules in solution in their cells. Unfortunately, many toxic substances also dissolve well in water, which makes them easy to transport through the environment.

Acids, Bases, and pH Another important property of water is its ability to dissolve hydrogen- or hydroxide-containing compounds known as acids and bases. An acid is a substance that contributes hydrogen ions to a solution. A base is a substance that contributes hydroxide ions to a solution.

Both acids and bases typically dissolve in water. Bases, on the other hand, dissociate into negatively charged hydroxide ions OH— and positively charged ions. Some examples of bases are sodium hydroxide NaOH and calcium hydroxide Ca OH 2 , which can be used to neutralize acidic emissions from power plants.

The pH scale is a way to indicate the strength of acids and bases. A pH value of 7 on this scale—the pH of pure water—is neutral, meaning that the number of hydrogen ions is equal to the number of hydroxide ions. Anything above 7 is basic, or alkaline, and anything below 7 is acidic. The lower the number, the stronger the acid, and the higher the number, the more basic the substance is. The pH scale is logarithmic, meaning that there is a factor of 10 difference between each number on the scale.

The pH scale is a way of expressing how acidic or how basic a solution is. In a chemical reaction, no atoms are ever destroyed or created. The bonds between particular atoms may change, however. For example, when methane CH4 is burned in air, it reacts with two molecules of oxygen 2 O2 to create one molecule of carbon dioxide CO2 and two molecules of water 2 H2O : Household bleach Sodium hydroxide Neutral Chemical Reactions and the Conservation of Matter Notice that the number of atoms of each chemical element is the same on each side of the reaction.

Chemical reactions can occur in either direction. For example, during the combustion of fuels, nitrogen gas N2 combines with oxygen gas O2 from the atmosphere to form two molecules of nitrogen oxide NO , which is an air pollutant: 14 12 10 times the hydrogen ion concentration of a substance with a pH of 6 it is 10 times more acidic.

For example, when paper burns, it may seem to vanish, but no atoms are lost; the carbon and hydrogen that make up the paper combine with oxygen in the air to produce carbon dioxide, water vapor, and other materials, which either enter the atmosphere or form ash. Combustion converts most of the solid paper into gases, but all of the original atoms remain. The only known exception to the law of conservation of matter occurs in nuclear reactions, in which small amounts of matter change into energy.

The law of conservation of matter tells us that we cannot easily dispose of hazardous materials. For example, when we burn material that contains heavy metals, such as an automotive battery, the atoms of the metals in the battery do not disappear. They turn up elsewhere in the environment, where they may cause a hazard to humans and other organisms. For this and other reasons, understanding the law of conservation of matter is crucial to environmental science.

Even though this forest seems to be disappearing as it burns, all the matter it contains is conserved in the form of water vapor, carbon dioxide, and solid particles. To further our understanding of chemical compounds, we will divide them into two basic types: inorganic and organic. Inorganic compounds are compounds that either a do not contain the element carbon or b do contain carbon, but only carbon bound to elements other than hydrogen.

Organic compounds are compounds that have carbon-carbon and carbon-hydrogen bonds. Organic compounds are the basis of the biological molecules that are important to life: carbohydrates, proteins, nucleic acids, and lipids. Because these four types of molecules are relatively large, they are also known as macromolecules.

Cellulose is the raw material for cellulosic ethanol, a type of fuel that has the potential to replace or supplement gasoline. Proteins are critical components of living organisms, playing roles in structural support, energy storage, internal transport, and defense against foreign substances.

Enzymes are proteins that help control the rates of chemical reactions. The antibodies that protect us from infections are also proteins. DNA deoxyribonucleic acid is the genetic material organisms pass on to their offspring that contains the code for reproducing the components of the next generation. Glucose C6H12O6 is a simple sugar a monosaccharide, or single sugar easily used by plants and animals for quick energy. For example, plants store energy as starch, which is made up of long chains of covalently bonded glucose molecules.

The starch can also be used by animals that eat the plants. Cellulose, a component of plant leaves and stems, is another LIPIDS Lipids are smaller biological molecules that do not mix with water. Fats, waxes, and steroids are all lipids. Lipids form a major part of the membranes that surround cells. But how do they work as part of a living organism? The smallest structural and functional component of organisms is known as a cell. Some organisms, such as most bacteria and some algae, consist of a single cell.

That one cell contains all of the functional structures, or organelles, needed to keep the cell alive and allow it to reproduce FIGURE 2. In what ways do those properties make life possible on Earth? Energy is the ability to do work, or transfer heat. Water flowing into a lake has energy because it moves and can move other objects in its path. All living systems absorb energy from their surroundings and use it to organize and reorganize molecules within their cells and to power movement.

The sugars in plants are also an important energy source for many animals. Humans, like other animals, absorb the energy they need for cellular respiration from food.

This provides the energy for our daily activities, from waking to sleeping and everything in between. Ultimately, most energy on Earth derives from the Sun.

The Sun emits electromagnetic radiation, a form of energy that includes, but is not limited to, visible light, ultraviolet light, and infrared energy, which we perceive as heat. Electromagnetic radiation is carried by photons, massless packets of energy that travel at the speed of light and can move even through the vacuum of space.

The amount of energy contained in a photon depends on its wavelength—the distance between two peaks or troughs in a wave, as shown in the inset in Figure 2. Photons with long wavelengths, such as radio waves, have very low energy, while those with short wavelengths, such as X-rays, have high energy. Photons of different wavelengths are used by humans for different purposes.

Forms of Energy The basic unit of energy in the metric system is the joule abbreviated J. A joule is the amount of energy used when a 1-watt light bulb is turned on for 1 second—a very small amount. Although the joule is the preferred energy unit in scientific study, many other energy units are commonly used. Conversions between these units and joules are given in Table 2. The majority of radiation produced by the Sun lies within this range.

The kilowatt kW is a unit of power. The kilowatt-hour kWh is a unit of energy. Your monthly home electricity bill reports energy use—the amount of energy from electricity that you have used in your home—in kWh. TABLE 2. Many stationary objects possess a large amount of potential energy—energy that is stored but has not yet been released.

Water impounded behind a dam contains a great deal of potential energy. When the water is released and flows downstream, that potential energy becomes kinetic energy, the energy of motion FIGURE 2. The kinetic energy of moving water can be captured at a dam and transferred to a turbine and generator, and ultimately to the energy in electricity.

Can you think of other common examples of kinetic energy? A car moving down the street, a flying honeybee, and a football travelling through the air all have kinetic energy. Sound also has kinetic energy because it travels in waves through the coordinated motion of atoms. Systems can contain potential energy, kinetic energy, or some of each. The water stored behind this dam has potential energy.

Each of the 30 chapters are covered in readings of two to five pages long. Additionally, the book provides access to a very complete glossary of terms used in environmental science. As a result, many Governments have introduced this as an essential part of the curriculum at both school and undergraduate level. The curriculum aims to discuss the discipline, its issues and problems and the remedial measures there of.

This textbook has thus been designed to provide comprehensive, relevant and up-to-date information in simple and lucid form, enriched with authoritative illustrations and case studies. Author : Jay H. We have distilled the most essential content from our full-length book, Environment: The Science behind the Stories, now in its sixth edition.

We have streamlined our material, updated our coverage, and carefully crafted our writing to make Essential Environment every bit as readable, informative, and engaging as its parent volume" Author : Edward A. Find Your School. No active courses are available for this school.

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