Properties of New Materials | Grade 6 | Unit 2 - Concept 2 - Lesson 6 | Science скачать в хорошем качестве

Properties of New Materials | Grade 6 | Unit 2 - Concept 2 - Lesson 6 | Science

شرح ساينس الصف السادس الابتدائي لغات - الفصل الدراسي الأول شرح ساينس سادسة ابتدائي - ترم أول لينك تحميل الملزمة https://drive.google.com/file/d/1Hi8F... لينك تليجرام https://t.me/mrahmedelbashagroup In This Lesson: People need different materials for different purposes. ► Every material is useful for some purposes not for all purposes, so scientists and engineers try to choose the most useful and suitable materials with some useful properties such as flexibility and conducting heat to make the products that people want. Examples: 1. When making cloth, scientists use soft materials. 2. When making a bicycle or a car, engineers cannot use cloth. ► Scientists and engineers always work to create or improve new materials for different and new purposes. Sometimes, when scientists develop a new materials, they focus on some specific properties of a material that they want develop. Example: • Scientists develop a smart material which is a flexible fabric that keeps the temperature of the body. • These smart materials are used in making smart clothes that can Control your body temperature. Light up in the dark. Keep themselves clean. How are new materials created? Scientists make new materials by mixing different materials together. Examples: 1. Steel: It is made of a mixture of iron and other elements. It is strong and lasts for a long time. 2. Concrete: It is made of a mixture of rock, sand and water. It is a liquid until it dries, it becomes hard. It is used as the base of buildings and bridges because it is very strong. ► - In some cases, the new materials are created due to the chemical change. When chemical change happens, the properties of the new materials differ from the properties of the original material. Example: Plastic is made by chemical change of some of the compounds in petroleum. ► In some other cases, the new materials are created by mixing materials at high temperatures. Examples: 1. Shrink-wrap is created when we add heat to plastic to make it shrink. 2. Glass is made from a mixture of sand with small amount of other materials such as limestone and soda ash (sodium carbonate). Glass is made when the sand mixture is heated in hot furnace so, it melts and changes into glass. Then the glass becomes hard when it cools. بالتوفيق مستر احمد الباشا