Grade 4 | Big City Environmental Concerns | Theme 3 - Concept 2 - Lesson 4 | Science

شرح ساينس الصف الرابع الابتدائي لغات - الفصل الدراسي الثاني شرح ساينس رابعة ابتدائي - ترم ثاني لينك تحميل الملزمة https://drive.google.com/file/d/1AW7U... لينك تليجرام https://t.me/mrahmedelbashagroup In This Lesson: Some sources of pollution in big cities 1. Smog produced from burning of fuels pollutes the air. 2. Pesticides used on farms are mixed with water in canals and rivers when rain falls, this lead to pollution of soil and water. 3. Chemicals used in many factories pollute the air and also the nearby water and soil. Some effects (impacts) of air pollution on human's health 1. Smog from cars cause irritation of human's eyes and lungs. 2. Scientists have found that smog contains tiny particles that the human breathes in, these particles irritate the lungs, causing the damage of tissues of the respiratory system. Harms of burning of fossil fuels on the environment Although burning fuel is used to generate electricity, but it makes pollution, where burning coal and oil produces carbon dioxide gas which causes: 1. Acid rains Carbon dioxide gas can combine with water in the air to form acid rain that leads to: The death of trees. The change in the chemical nature of lakes and kill fish. The change in the chemical nature of soil. Dissolving some rocks including the rocks used for building. 2. Global warming Increasing the amount of carbon dioxide gas in the air forms a layer in the atmosphere that traps heat above the Earth 's surface causing a slow rise in the Earth's temperature , which is known as global warming. Disadvantages of using fossil fuels to produce energy: • When some forms of fossil fuels are burned, they release gases that cause: -Air pollution. Trap heat in the atmosphere causing "global warming" which raises the temperature of Earth and changes its climate. بالتوفيق مستر احمد الباشا