Answer:
Pure Substances: Salt, Sugar, Iron, Copper, Oxygen
Mixtures: Water, Air, Juice, Salad, Coffee
Burning of a Candle:
Both (Physical and Chemical)
Applications of Separation Techniques:
Centrifugation: Blood, Enzymes, Cream
Sublimation: Solids, Dry ice, Purification
Evaporation: Salt, Concentration, Drying
Chromatography: Pigments, Drugs, Amino acids
Fractional Distillation: Oil, Alcohol, Gases
Step-by-step explanation:
1) Segregation of Pure Substances and Mixtures around me:
- Pure Substances: Salt, Sugar, Iron rod, Copper wire, Oxygen gas
- Mixtures: Tap water, Air, Orange juice, Salad, Coffee
2) Burning of a candle is both physical and chemical change. Initially, the wax in the candle is in solid form which melts when its temperature rises due to the heat of the flame. This is a physical change. The melted wax then moves up the wick by capillary action and gets vaporized by the heat of the flame. This is a chemical change, as the wax molecules break down into simpler molecules such as carbon dioxide and water vapor, which are released into the air. The heat and light given off by the candle are also evidence of a chemical change taking place.
3) Applications of Separation Techniques:
- Centrifugation: Separation of blood components, purification of enzymes, separation of cream from milk
- Sublimation: Purification of solids, separation of substances with different vapor pressures, production of dry ice
- Evaporation: Separation of salt from seawater, concentration of fruit juices, drying of wet clothes
- Chromatography: Separation of pigments in plants, detection of drugs in urine samples, analysis of amino acids in proteins
- Fractional Distillation: Separation of crude oil into its components, purification of alcohol, separation of different gases in air
Note: There are other applications for each of these separation techniques as well.