Read the text to answer. 

Acid rain and… the facts

www.acidrain.org.ca / Oxford Children´s Encyclopedia

What causes acid rain?

Acid rain is caused by air pollution. When fossil fuels such as coal and oil are burned, two gases, sulphur dioxide and nitrogen oxide, are released into the atmosphere. These two pollutants eventually react with the moisture in the air. When this polluted mixture falls onto the ground, it is called acid rain.

Rain measuring between 0 and 5 on the pH scale, is acidic therefore called ACID RAIN

Acid rain is harmful to the environment. It is hard to control because it may be blown by the wind, falling thousands of kilometers from where it was first formed. For example, much of the acid rain in Canada is caused by smoke from factories and power‐stations in the USA. The acid rain in Scandinavia may come from Britain.

What are the effects of acid rain?

Acid rain has many different effects. It has killed fish in the lakes of North America, Scandinavia, Scotland, and Wales. Vast areas of forest in northern and central Europe are dying because of it, while in many European cities statues and stone buildings are being eaten away by the acid. Acid rain corrodes metalwork such as steel bridges and railings; it also attacks some types of concrete. Even the water that we drink is slowly being polluted by acid rain.  

What are the effects on trees and soil?

One of the most serious impacts of acid precipitation is on forests and soils. Great damage is done when sulphuric acid falls onto the earth as rain. Nutrients present in the soils are washed away. Aluminium also present in the soils is freed and this toxic element can be absorbed by the roots of trees. Thus, the trees starve to death because they have been deprived of their vital nutrients such as calcium and magnesium.

Acid rain is one of the most serious environmental problems of our time. It is a global problems that is gradually affecting our world.

How does acid rain effect lakes?

Lakes that have been acidified cannot support the same variety of life as healthy lakes. As a lake becomes more acidic, various types of fish disappear. Other effects of acidified lakes on fish include: decreased growth, inability to regulate their own body chemistry, reduced egg deposition, deformities in young fish and increased susceptibility to naturally occurring diseases.     

Clean rain usually has a pH of 5.6. It is slightly acidic because of carbon dioxide which is naturally present in the atmosphere. Vinegar, by comparison, is very acidic and has a pH of 3.

What is pH?

This is a measure of how acidic or alkaline a substance is. (See a pH scale below). The initials pH stand for Potential of Hydrogen. Acids have pH values under 7, and alkalis have pH values over 7. If a substance has a pH value of 7. It is neutral‐neither acidic or alkaline.    

Because the pH scale is logarithmic, a difference of one pH unit represents a tenfold, or ten times change. For example, the acidity of a sample with a pH of 5 is ten times greater than that of a sample with a pH of 6. A difference of 2 units, from 6 to 4, would mean that the acidity in one hundred times greater, and so on.

Read the text to answer. 

Acid rain and… the facts

www.acidrain.org.ca / Oxford Children´s Encyclopedia

What causes acid rain?

Acid rain is caused by air pollution. When fossil fuels such as coal and oil are burned, two gases, sulphur dioxide and nitrogen oxide, are released into the atmosphere. These two pollutants eventually react with the moisture in the air. When this polluted mixture falls onto the ground, it is called acid rain.

Rain measuring between 0 and 5 on the pH scale, is acidic therefore called ACID RAIN

Acid rain is harmful to the environment. It is hard to control because it may be blown by the wind, falling thousands of kilometers from where it was first formed. For example, much of the acid rain in Canada is caused by smoke from factories and power‐stations in the USA. The acid rain in Scandinavia may come from Britain.

What are the effects of acid rain?

Acid rain has many different effects. It has killed fish in the lakes of North America, Scandinavia, Scotland, and Wales. Vast areas of forest in northern and central Europe are dying because of it, while in many European cities statues and stone buildings are being eaten away by the acid. Acid rain corrodes metalwork such as steel bridges and railings; it also attacks some types of concrete. Even the water that we drink is slowly being polluted by acid rain.  

What are the effects on trees and soil?

One of the most serious impacts of acid precipitation is on forests and soils. Great damage is done when sulphuric acid falls onto the earth as rain. Nutrients present in the soils are washed away. Aluminium also present in the soils is freed and this toxic element can be absorbed by the roots of trees. Thus, the trees starve to death because they have been deprived of their vital nutrients such as calcium and magnesium.

Acid rain is one of the most serious environmental problems of our time. It is a global problems that is gradually affecting our world.

How does acid rain effect lakes?

Lakes that have been acidified cannot support the same variety of life as healthy lakes. As a lake becomes more acidic, various types of fish disappear. Other effects of acidified lakes on fish include: decreased growth, inability to regulate their own body chemistry, reduced egg deposition, deformities in young fish and increased susceptibility to naturally occurring diseases.     

Clean rain usually has a pH of 5.6. It is slightly acidic because of carbon dioxide which is naturally present in the atmosphere. Vinegar, by comparison, is very acidic and has a pH of 3.

What is pH?

This is a measure of how acidic or alkaline a substance is. (See a pH scale below). The initials pH stand for Potential of Hydrogen. Acids have pH values under 7, and alkalis have pH values over 7. If a substance has a pH value of 7. It is neutral‐neither acidic or alkaline.    

Because the pH scale is logarithmic, a difference of one pH unit represents a tenfold, or ten times change. For example, the acidity of a sample with a pH of 5 is ten times greater than that of a sample with a pH of 6. A difference of 2 units, from 6 to 4, would mean that the acidity in one hundred times greater, and so on.

Everyone keeps data. Big organizations spend millions to look after their payroll, customer and transaction data. The penalties for getting it wrong are severe: businesses may collapse, shareholders and customers lose money, and for many organizations (airlines, health boards, energy companies), it is not exaggerating to say that even personal safety may be put at risk. And then there are the lawsuits. The problems in successfully designing, installing, and maintaining such large databases are the subject of numerous books on data management and software engineering. However, many small databases are used within large organizations and also for small businesses, clubs, and private concerns. When these go wrong, it doesn't make the front page of the papers; but the costs, often hidden, can be just as serious.

 Where do we find these smaller electronic databases? Sports clubs will have membership information and match results; small businesses might maintain their own customer data. Within large organizations, there will also be a number of small projects to maintain data information that isn't easily or conveniently managed by the large system-wide databases. Researchers may keep their own experiment and survey results; groups will want to manage their own rosters or keep track of equipment; departments may keep their own detailed accounts and submit just a summary to the organization's financial software.

Most of these small databases are set up by end users. These are people whose main job is something other than that of a Computer professional. They will typically be scientists, administrators, technicians, accountants, or teachers, and many will have only modest skills when it comes to spreadsheet or database software. 

The resulting databases often do not live up to expectations. Time and energy is expended to set up a few tables in a database product such as Microsoft Access, or in setting up a spreadsheet in a product such as Excel. Even more time is spent collecting and keying in data. But invariably (often within a short time frame) there is a problem producing what seems to be a quite simple report or query. Often this is because the way the tables have been set up makes the required result very awkward, if not impossible, to achieve. 

A database that does not fulfill expectations becomes a costly exercise in more ways than one. We clearly have the cost of the time and effort expended on setting up an unsatisfactory application. However, a much more serious problem is the unability to make the best use of valuable data. This is especially so for research data. Scientific and social researchers may spend considerable money and many years designing experiments, hiring assistants and collecting and analyzing data, but often very little thought goes into storing it in an appropriately designed database. Unfortunately, some quite simple mistakes in design can mean that much of the potential information is lost. The immediate objective may be satisfied, but unforeseen uses of the data may be seriously compromised. Next year's grant opportunities are lost.

Everyone keeps data. Big organizations spend millions to look after their payroll, customer and transaction data. The penalties for getting it wrong are severe: businesses may collapse, shareholders and customers lose money, and for many organizations (airlines, health boards, energy companies), it is not exaggerating to say that even personal safety may be put at risk. And then there are the lawsuits. The problems in successfully designing, installing, and maintaining such large databases are the subject of numerous books on data management and software engineering. However, many small databases are used within large organizations and also for small businesses, clubs, and private concerns. When these go wrong, it doesn't make the front page of the papers; but the costs, often hidden, can be just as serious.

 Where do we find these smaller electronic databases? Sports clubs will have membership information and match results; small businesses might maintain their own customer data. Within large organizations, there will also be a number of small projects to maintain data information that isn't easily or conveniently managed by the large system-wide databases. Researchers may keep their own experiment and survey results; groups will want to manage their own rosters or keep track of equipment; departments may keep their own detailed accounts and submit just a summary to the organization's financial software.

Most of these small databases are set up by end users. These are people whose main job is something other than that of a Computer professional. They will typically be scientists, administrators, technicians, accountants, or teachers, and many will have only modest skills when it comes to spreadsheet or database software. 

The resulting databases often do not live up to expectations. Time and energy is expended to set up a few tables in a database product such as Microsoft Access, or in setting up a spreadsheet in a product such as Excel. Even more time is spent collecting and keying in data. But invariably (often within a short time frame) there is a problem producing what seems to be a quite simple report or query. Often this is because the way the tables have been set up makes the required result very awkward, if not impossible, to achieve. 

A database that does not fulfill expectations becomes a costly exercise in more ways than one. We clearly have the cost of the time and effort expended on setting up an unsatisfactory application. However, a much more serious problem is the unability to make the best use of valuable data. This is especially so for research data. Scientific and social researchers may spend considerable money and many years designing experiments, hiring assistants and collecting and analyzing data, but often very little thought goes into storing it in an appropriately designed database. Unfortunately, some quite simple mistakes in design can mean that much of the potential information is lost. The immediate objective may be satisfied, but unforeseen uses of the data may be seriously compromised. Next year's grant opportunities are lost.

Everyone keeps data. Big organizations spend millions to look after their payroll, customer and transaction data. The penalties for getting it wrong are severe: businesses may collapse, shareholders and customers lose money, and for many organizations (airlines, health boards, energy companies), it is not exaggerating to say that even personal safety may be put at risk. And then there are the lawsuits. The problems in successfully designing, installing, and maintaining such large databases are the subject of numerous books on data management and software engineering. However, many small databases are used within large organizations and also for small businesses, clubs, and private concerns. When these go wrong, it doesn't make the front page of the papers; but the costs, often hidden, can be just as serious.

 Where do we find these smaller electronic databases? Sports clubs will have membership information and match results; small businesses might maintain their own customer data. Within large organizations, there will also be a number of small projects to maintain data information that isn't easily or conveniently managed by the large system-wide databases. Researchers may keep their own experiment and survey results; groups will want to manage their own rosters or keep track of equipment; departments may keep their own detailed accounts and submit just a summary to the organization's financial software.

Most of these small databases are set up by end users. These are people whose main job is something other than that of a Computer professional. They will typically be scientists, administrators, technicians, accountants, or teachers, and many will have only modest skills when it comes to spreadsheet or database software. 

The resulting databases often do not live up to expectations. Time and energy is expended to set up a few tables in a database product such as Microsoft Access, or in setting up a spreadsheet in a product such as Excel. Even more time is spent collecting and keying in data. But invariably (often within a short time frame) there is a problem producing what seems to be a quite simple report or query. Often this is because the way the tables have been set up makes the required result very awkward, if not impossible, to achieve. 

A database that does not fulfill expectations becomes a costly exercise in more ways than one. We clearly have the cost of the time and effort expended on setting up an unsatisfactory application. However, a much more serious problem is the unability to make the best use of valuable data. This is especially so for research data. Scientific and social researchers may spend considerable money and many years designing experiments, hiring assistants and collecting and analyzing data, but often very little thought goes into storing it in an appropriately designed database. Unfortunately, some quite simple mistakes in design can mean that much of the potential information is lost. The immediate objective may be satisfied, but unforeseen uses of the data may be seriously compromised. Next year's grant opportunities are lost.