How Do Rocks Provide Building Materials

Chemistry 1 Revision Booklet Unit Chemistry 1 Syllabus
At the beginning of each sub-section, activities are stated which develop candidates. skills, knowledge and understanding of how science works. Details are then given of the substantive contexts in which these skills, knowledge and understanding should be set. It is expected that, where appropriate, teachers will adopt a practical approach, enabling candidates to develop skills in addition to procedural knowledge and understanding. Note that objective test Chemistry 1a examines Section 11.1 . 11.3 and objective test Chemistry 1b examines Sections 11.4 . 11.6. 11.1 How do rocks provide building materials? The exploitation of rocks provides essential building materials. Limestone is a naturally
The plant material is crushed and the oil removed by pressing or in some cases by distillation. Water and other impurities are removed. Vegetable oils are important foods and fuels as they provide a lot of energy. They also provide us with nutrients. Oils do not dissolve in water. They can be used to produce emulsions. Emulsions are thicker than oil or water and have many uses that depend on their special properties. They provide better texture, coating ability and appearance, for example in salad dressings and ice creams. Vegetable oils that are unsaturated contain double carbon carbon bonds. These can be detected by reacting with bromine or iodine. Vegetable oils that are unsaturated can be hardened by reacting them with hydrogen in the presence of a nickel catalyst at about 60 °C. The hydrogenated oils have higher melting points so they are solids at room temperature, making them useful as spreads and in cakes and pastries. Processed foods may contain additives to improve appearance, taste and shelf-life. These additives must be listed in the ingredients and some permitted additives were given E-numbers. Chemical analysis can be used to identify additives in foods. Artificial colours can be detected and identified by chromatography. 11.6 What are the changes in the Earth and its atmosphere? The Earth and its atmosphere provide everything we need. The Earth has a layered structure. Large-scale movements of the Earth.s crust can cause changes in the rocks. The Earth.s atmosphere was originally very different from what it is today. It has been much the same for the last 200 million years and provides the conditions needed for life on Earth. Recently human activities have produced further changes. Candidates should use their skills, knowledge and understanding of how science works: to