form 3 chapter 6, the land and its resources (summary)

• The Earth's crust contains elements and compounds of minerals that exist naturally.
• Mierals are inactive element as they do not react with other elements easily.
• Compounds minerals are normally made up of metals and non-metals.
• Some of them are metal oxides, metal sulphides and metal carbonates.
• The properties of minerals are hardness, solubility in water and effect of heat.
• Metal oxides do not decompose when heated except silver ocide and mercury oxide that release oxygen.
• Metla sulphides decompose to produce metal oxides and sulphur dioxide gas when heated.
• Most metal react with oxygen to form metal oxides.
• Metals react with oxygen at different rates.
• Metals react at different rates with sulphur to produce metal sulphides.
• There are two types of silicon compounds, which are silica and silicate.
• Silica, or silicon dioxide is made up of silicon and oxygen. Some examples are sand ,quartz and flint.
• Silica is not soluble in water, does not decompose when heated, is acidic and reacts with alkali to produce silicate salt/
• Silica is used to make concrete, mortar, glass and ceramic tiles.
• Silicate consists of silicon, oxygen and metal.
• Examples of silicate are clay, feldsapre, mica, jade, asbestos and ruby.
• Silicate compounds are very stable. They are used to make bricks, cement, roof tiles, flower pots, heat insulator, fire proof clothes and accessories for ladies.
• Calcium is a reactive metal which reacts with other elements to form compounds
• Calcium carbonate consists of calcium, oxygen and carbon.
• Some natural form of calcium carbonate are coral, bone and teeth.
• Calcium carbonate does not dissolve in water. It reacts with acid to form calcium salt and carbon dioxide. It decomposes into calcium oxide and carbon dioxide when heated.
• When water is dripped on calcium oxide, calcium hydroxide is produced. Calcium hydroxide solution is produces when it dissolves in water.
• Carbon dioxide reacts with calcium hydroxide solution to produce a precipitate of calcium carbonate.
• Fossil fuels are petroleum, natural gas and coal.
• Petroleum and natural gas are made from remains of dead animals and plants over millions of years ago.
• The dead animals and plants settled to the bottom of sea. Eventually they were buried under mud and sand. High pressure and temperature slowly changed them into petroleum and natural gas.
• Fractional distillation is used to separate petroleum to different components based on their boiling points.
• The petroleum fas which is very volatile is collected first while bitumen is the last product.
• Petroleum can be separated to 8 different components and each of them has different uses.
• The petroleum industry is the major contributor to the development of Malaysian economy.
• Petroleum and natural gas are non-renewable sources of energy. Therefore, they must be used wisely and efficiently.
• Several ways can be done to conserve natural fuel such as the use of public transport, regular maintenance of vehicles, use of alternative sources of energy, development of more efficient vehicles and recycling of materials especially those related to the petrochemical industry.