Sửa từ sai

Cho 100ml dung dịch x gồm hcl 0,1M và h2so4 0,05m vào 100ml dung dịch y gồm naoh am và ba(oh)2 bm thu được dung dịch z và 1,0485 gam kết tủa. Cho z vào ba(hso3)2 dư thì thu được 0,9845 gam kết tủa. Tìm a,b

b. Khi tham gia phản ứng hóa học, nguyên tử Fe nhường 2 electron tạo thành ion Fe2+, có thể có các cấu hình electron như sau:

1s22s22p63s²3p63d44s²

(1)

1s22s22p63s23p63d6

(2)

Sử dụng công thức tính năng lượng AO của Slater, hãy cho biết cấu hình electron bền của ion Fe2+.

Nature gave us all necessary resources to live and prosper. Now it is in danger and needs our help. What else we can do to protect environment? First of all this decisions must be made on governmental level and provide legal limitations for industries that emit a lot of greenhouse gases. We must unite together in order to protect the place we live in. People are an integral part of nature, we are dependent of it as we cannot imagine our life without nature. So why to destroy environment and bite the hand that feeds you? We must stop deforestation and plant trees on cut down areas. Trees are natural filter of air that absorb carbon dioxide and produce oxygen. Cutting down trees we deprive animals of their natural environment and the soil begin to grow in erosion. Planting trees will save birds and other animals.

We often make forced choices that are advertised on TV. Manufacturers try to rise their profits and sell more products. Sometimes we have so many unnecessary things we do not use. Imagine that you are moving your house, what are the necessary items you may need to live, only several bags. In reality the matter is opposite. There are a lot of things we do not use. People have to reconsider their views of life and promote healthy and ecologically friendly lifestyle. It is up to us to change situation for better and leave good legacy for generations to come.

21. What is in danger and need our help?

   ……………………………………………………………………………………………….

22. Why should we plant trees?        ……………………………………………………………………………………………

23. What do the writer take moving house as an example for?

        ……………………………………………………………………………………………

24. What do people have to reconsider?

       …………………………………………………………………………………………….

Pollution is any contamination of the environment which causes harm to the environment or the inhabitants of the 

Soil pollution can be caused by pesticides, leakage from chemical tanks, oil spills, and other chemicals which get into the soil by dumping or accidental contamination. Soil pollution can also cause water pollution when underground water becomes contaminated by coming into contact with the polluted soil. Water pollution can be caused by waste products, sewage, oil spills, and litter in streams, rivers, lakes, and oceans. Some scientists believe that water pollution is the largest cause of death and disease in the world, causing about 14,000 deaths in the world each day.

It is not possible for anyone to predict the exact timing and effects of global pollution and global climate change brought about by pollution. There is general agreement by scientists that the global climate will continue to change, the intensity of weather effects will continue to increase, and some species of animals will become extinct

4. What kind of pollution may oil spills cause

3. What is cause of soil pollution

Pollution is any contamination of the environment which causes harm to the environment or the inhabitants of the environment. There are three main kinds of pollution. Air pollution can be caused by liquids, or gases that make the air harmful to breathe. There are two main types of air pollution: primary and secondary. Primary pollutants enter the air directly, like smoke from factories and car exhaust. Secondary pollutants are chemicals that mix together to pollute the air, like mixtures of emissions from vehicles and factory smoke that change to form more dangerous pollutants in the air and sunlight.

Soil pollution can be caused by pesticides, leakage from chemical tanks, oil spills, and other chemicals which get into the soil by dumping or accidental contamination. Soil pollution can also cause water pollution when underground water becomes contaminated by coming into contact with the polluted soil. Water pollution can be caused by waste products, sewage, oil spills, and litter in streams, rivers, lakes, and oceans. Some scientists believe that water pollution is the largest cause of death and disease in the world, causing about 14,000 deaths in the world each day.

It is not possible for anyone to predict the exact timing and effects of global pollution and global climate change brought about by pollution. There is general agreement by scientists that the global climate will continue to change, the intensity of weather effects will continue to increase, and some species of animals will become extinct

1.How many kinds of pollution are there in the text?

2.What kind of pollution is considered as the cause of the most death and disease?