MCQ Chapter 5 Class 7 Science Curiosity NCERT Advertisement Changes Around Us: Physical and Chemical 1. What type of change is the curdling of milk?Physical changeChemical changeNo changeBoth physical and chemical changeQuestion 1 of 202. What are the three requirements for combustion to occur?Fuel, oxygen, ignition temperatureFuel, water, heatOxygen, carbon dioxide, lightFuel, air, cold temperatureQuestion 2 of 203. What type of change occurs when dough is rolled into chapatis?Chemical changePhysical changeBoth physical and chemical changeNo changeQuestion 3 of 204. What is the new substance formed when lime water reacts with carbon dioxide?Calcium hydroxideCalcium carbonateSodium carbonateMagnesium oxideQuestion 4 of 205. Which of the following is a desirable change?Rusting of ironCooking of foodDecay of foodAtmospheric pollutionQuestion 5 of 206. What type of change is the ripening of fruits?Physical changeChemical changeNo changeBoth physical and chemical changeQuestion 6 of 207. What happens to the wax of a candle when it burns?It only meltsIt only evaporatesIt undergoes both physical and chemical changesIt remains unchangedQuestion 7 of 208. What is the process called when sediments harden over time to form new rocks?WeatheringErosionCombustionSedimentationQuestion 8 of 209. Which of the following is an undesirable change?Changing milk into curdRusting of ironRipening of fruitsCutting of fruitsQuestion 9 of 2010. What type of change is dissolving sugar in water?Chemical changePhysical changeBoth physical and chemical changeNo changeQuestion 10 of 2011. What is observed when lemon juice is used as invisible ink and heated?The paper catches fireThe letters turn dark brownThe paper dissolvesThe letters disappear completelyQuestion 11 of 2012. What type of change is the decomposition of vegetable peels into compost?Physical changeChemical changeNo changeBoth physical and chemical changeQuestion 12 of 2013. What is the role of yeast in baking bread?It changes the color of breadIt produces carbon dioxide to make bread fluffyIt dissolves sugar in waterIt hardens the doughQuestion 13 of 2014. What type of change is the germination of seeds into plants?Physical changeChemical changeNo changeBoth physical and chemical changeQuestion 14 of 2015. What is the color change observed in basalt rock due to weathering?From black to greenFrom black to redFrom red to blackFrom green to blackQuestion 15 of 2016. Which of the following changes cannot be reversed?Boiling waterMaking idlis from batterFolding a handkerchiefTwisting a stringQuestion 16 of 2017. What is the best way to extinguish a fire on a person’s clothes?Pour water on themWrap a blanket around themBlow air on the fireUse a synthetic clothQuestion 17 of 2018. What type of change is the smoothing of river rocks due to flowing water?Chemical changePhysical changeBoth physical and chemical changeNo changeQuestion 18 of 2019. What is bioluminescence, as described in the document?Light produced by heat in living organismsLight produced by a chemical change without heatLight produced by physical changesLight produced by combustionQuestion 19 of 2020. Which of the following experiments results in lime water turning milky?Mixing vinegar and common saltMixing lemon juice and vinegarMixing lemon juice and baking sodaMixing vinegar and waterQuestion 20 of 20 Loading...
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