ANS TO TEXTBOOK QUESTION
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Homogenous - Fog, Idli batter
Heterogeneous - Vegetable poha, Oil and water, Salad
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Handpicking
Threshing
Handpicking
Winnowing
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False
True
False
False
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Magnet
The Mixture of a solute and solvent is a solution.
Saturated solution
Answers to Let’s Exercise questions
Chose the correct option Threshing Evaporation Freezing the solution Smoke Filtration
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Fill in the blanks with the given words in the brackets Visible Blowing air Husk, grains Solute gas
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State whether the following statements are true or false True False False False False
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Answer the following questions in short Smoke, storms A magnet can attract magnetic materials. The materials which are not attracted by a magnet are known as non-magnetic materials. When we come across a mixture of magnetic and non-magnetic materials, we can use a magnet for separating the mixture. Separation of mixtures into their constituents is often necessary for removal of undesirable substance and separation of useful components. A pure substance is a homogeneous material with a definite, fixed chemical composition. While impure substances are mixtures of two or more elements or compounds or both. Components of a pure substance cannot be separated by physical methods of separation while components of a impure substance can be separated by physical methods of separations such as - magnetic separation, evaporation, etc.
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Define the following A saturated solution is a chemical solution containing the maximum concentration of a solute dissolved in the solvent. When a liquid changes to gas, the process is called as evaporation. When a gas changes into liquid, the process is called as condensation. Decantation is a process in which the clear liquid is transferred to another container without disturbing the sediments. A mixture is a substance made by combining two or more pure substances in such a way that no chemical reaction occurs.
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Answer the following questions in detail The different methods used to separating solid-solid mixtures are – Handpicking – it involves simply picking out substances by hand and separating them from others. Handpicking is not preferred if the quantity of the mixture to be separated is too large. Handpicking can only be used if the impurities are visible and large enough to be picked out. Threshing – is used to separate the seeds or grains from the stalks of the plants. Winnowing -The method of separating heavier and lighter components of a mixture by wind or blowing air is called winnowing. Chaff from the grains is separated by blowing air. Sieving- when the components of a mixture are of different sizes, a sieve can be used to separate them. A sieve is a shallow vessel that has small holes at its bottom. The size of the holes in the sieve depends on the size of the components to be separated. The method of separating the components of a mixture that are of different sizes by using a sieve is called sieving.
Evaporation is used for separating a mixture of a soluble solid and a solvent. The process involves heating the solution until the solvent evaporates leaving behind the solid residue. The water vapor can be condensed to collect the water. Mixture is a combination of two or more substances to make either a compound or a solution. It has two major types: A homogeneous mixture is a mixture where the components that make up the mixture are uniformly distributed throughout the mixture. A heterogeneous mixture is a mixture where the components of the mixture are not uniform.
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Diagram based question A- oil B- water
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HOTS We see water droplets outside of a cold glass or bottle because of condensation of water vapours. River water is constantly being restocked by fresh water from rain and springs, thus they do not taste salty. But the sea collects all of the river water salt and minerals from all of the rivers that flow into it and becomes saltier. Hence, River water is sweet while sea water is salty.
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