Sec.1 (1st term ) lesson 1.pdf

Integrated Science st TheII 1 Secondary Grade Intgrated science First Term Name: ______________________________ Class: _______________________________...

Integrated Science st TheII 1 Secondary Grade Intgrated science First Term Name: ______________________________ Class: _______________________________ 01063200774 1 ENG / Mahmoud FATHY  Integrated Science st TheII 1 Secondary Grade Chapter 1 Aquatic Ecosystem Lesson 1 : Chemical reactions and their effect on water quality pierts Water has unique properties that support life as : 1-Water can dissolve many chemicals 2- can exist in three states of matter solid, liquid, and gaseous, within the temperature range known on Earth. 3-Water is essential for life on Earth. 4-All living organisms have a membrane that separates the organism from its environment. What is the importance of the cell membrane in the living organisms? Water can passes from the environment into the living cell through this membrane, carrying the materials needed to produce energy and also to remove waste to the outside. Different Spheres on Earth planet Earth is characterized by hydrosphere than other planets in the solar system -Water covers about 70% of the Earth's surface. About 97% of this liquid water is found in oceans, seas, and salt lakes as salt water. The remain part is fresh water found in rivers, lakes, and groundwater. 01063200774 2 ENG / Mahmoud FATHY  Integrated Science st TheII 1 Secondary Grade - Water vapor (water in the gaseous state) is considered one of the components of the atmosphere. - the cryosphere, which refers to the frozen water in the polar regions, mountain peaks, and Glaciers -Egypt is characterized by the diversity of its aquatic environments, which include the Nile River, the Gulf of Suez, the Gulf of Aqaba, the Red Sea, the Mediterranean Sea, and many salt and freshwater lakes. Water cycle in nature -Water exists on earth surface or near the Earth's surface, it changes between its three states (water vapor, solid , liquid) Water is constantly moving from one place to another through many different paths that form a closed system called the water cycle in nature or the hydrological cycle and the water cycle as a system can changing the Earth's surface physically, chemically and biologically. The water cycle in nature mainly includes the process of : 1- evaporation, which contributes to the formation of clouds, 2- rain or snow falling 3- other biological processes such as transpiration in plants and respiration of plants and animals 4- processes of water leakage through the pores of soil and sedimentary rocks to form groundwater. Note : Water vapor in clouds may react chemically with compounds found in the air, forming acids that fall as acid rain, which dissolves the rocks 01063200774 3 ENG / Mahmoud FATHY  Integrated Science st TheII 1 Secondary Grade Chemical structure of water: Water is composed of two elements, hydrogen and oxygen, in a ratio of 2:1 volume respectively - Oxygen represents 88.89% of the mass of a water molecule -Hydrogen represents 11.11% of the mass of a water molecule The two hydrogen atoms are linked to the oxygen atom by two covalent bonds, between which an angle measuring about 104.5 Chemical properties of water: Water does not exist on the Earth's surface in a pure form, as it contains many ions and Chemical substances that interact with water by different ways. From the chemical properties of water: 1-Polarity of water: The oxygen atom is characterized by its higher electronegativity than the hydrogen atom, so the electrons of bond are attracted towards the oxygen atom, forming a partial negative charge on the oxygen atom and a partial positive charge on the hydrogen atom, which is known as polarity of water molecule. What are the consequences of the polarity of water molecule? The polarity of water molecules causes: 1- Their bending with other water molecules which is called hydrogen bonds 2-Gives water the ability to dissolve many salts and break them down into hydrated ions 01063200774 4 ENG / Mahmoud FATHY  Integrated Science st TheII 1 Secondary Grade EX : solubility of Sodium chloride in water: Give reason for The high boiling point of pure water, reaches 100 C? Due to the ability of water molecules to form hydrogen bonds between its molecules -high boiling point of pure water, which reaches 100 C under normal atmospheric pressure compared to the temperature of Water Compared to the Boiling point of compounds similar to it in composition, such as hydrogen sulfide, which boils at 61 -. 01063200774 5 ENG / Mahmoud FATHY