{"id":17094,"date":"2022-02-04T14:43:12","date_gmt":"2022-02-04T09:13:12","guid":{"rendered":"https:\/\/apboardsolutions.com\/?p=17094"},"modified":"2023-03-29T17:22:55","modified_gmt":"2023-03-29T11:52:55","slug":"ap-board-7th-class-science-solutions-10th-lesson","status":"publish","type":"post","link":"https:\/\/apboardsolutions.com\/ap-board-7th-class-science-solutions-10th-lesson\/","title":{"rendered":"AP Board 7th Class Science Solutions 10th Lesson Changes Around Us"},"content":{"rendered":"

SCERT AP 7th Class Science Study Material Pdf<\/a> 10th Lesson Changes Around Us Textbook Questions and Answers.<\/p>\n

AP State Syllabus 7th Class Science 10th Lesson Questions and Answers Changes Around Us<\/h2>\n

7th Class Science 10th Lesson Changes Around Us Textbook Questions and Answers<\/h3>\n

Improve Your Learning<\/span><\/p>\n

I. Fill in the blanks.<\/span><\/p>\n

1. Changes in which new substances are formed are called ______ changes.
\n2. Magnesium + Oxygen \u2192 ______
\n3. Milk converted to curd is ______ change.
\n4. Rusting of iron is protected by ______ process.
\nAnswer:
\n1. Chemical
\n2. Magnesium Oxide
\n3. Chemical
\n4. Galvanisation<\/p>\n

II. Choose the correct answer.<\/span><\/p>\n

1. When a woolen yarn is knitted to get a sweater, the change can be described as
\na) Physical change
\nb) Chemical change
\nc) Endothermic reaction
\nd) Exothermic reaction
\nAnswer:
\na) Physical change<\/p>\n

2. The chemical chancre among the following is ______
\na) Water to clouds
\nb) GroWth of a tree
\nc) Cow dung to bio gas
\nd) Ice to water
\nAnswer:
\nb) GroWth of a tree<\/p>\n

3. Which is an example of a periodic change?
\na) Earth quake
\nb) Formation of rainbow
\nc) Occurrence of tides in sea
\nd) Showering of rain
\nAnswer:
\nc) Occurrence of tides in sea<\/p>\n

\"AP<\/p>\n

4. Photosynthesis by green plant is a
\na) Physical change
\nb) Chemical change
\nc) Reversible change
\nd) None of the above
\nAnswer:
\nb) Chemical change<\/p>\n

III. Matching.<\/span><\/p>\n\n\n\n\n\n\n\n\n\n
Group – A<\/td>\nGroup – B<\/td>\n<\/tr>\n
A) Growing hair<\/td>\n1. Chemical change<\/td>\n<\/tr>\n
B) Breaking Mirror<\/td>\n2. Acetic Acid<\/td>\n<\/tr>\n
C) Galvanisation<\/td>\n3. Slow change<\/td>\n<\/tr>\n
D) Vinegar<\/td>\n4. Physical change<\/td>\n<\/tr>\n
E) Atmospheric pollution<\/td>\n5. Depositing zinc on iron metal<\/td>\n<\/tr>\n
<\/td>\n6. Fast change<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

Answer:<\/p>\n\n\n\n\n\n\n\n\n
Group – A<\/td>\nGroup – B<\/td>\n<\/tr>\n
A) Growing hair<\/td>\n3. Slow change<\/td>\n<\/tr>\n
B) Breaking Mirror<\/td>\n4. Physical change<\/td>\n<\/tr>\n
C) Galvanisation<\/td>\n5. Depositing zinc on iron metal<\/td>\n<\/tr>\n
D) Vinegar<\/td>\n2. Acetic Acid<\/td>\n<\/tr>\n
E) Atmospheric pollution<\/td>\n1. Chemical change<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

IV. Answer the following questions.<\/span><\/p>\n

Question 1.
\nDistinguish physical and chemical changes.
\nAnswer:<\/p>\n\n\n\n\n\n\n\n
Physical Changes<\/td>\nChemical Changes<\/td>\n<\/tr>\n
1) No new substances are formed.<\/td>\n1) During this new substances are formed.<\/td>\n<\/tr>\n
2) The chemical properties of a sub-stance do not change.<\/td>\n2) The chemical properties of a substance changes.<\/td>\n<\/tr>\n
3) It is temporary and reversible in nature.<\/td>\n3) It is permanent and irreversible change.<\/td>\n<\/tr>\n
4) Change in the properties such as colour, shape and size of a sub-stance occurs.<\/td>\n4) A colour change may take place and sound may be produced. Heat or light may be ab\u00acsorbed or released.<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

Question 2.
\nWhen a candle is burnt, what type of changes takes place? Give another example of the similar process.
\nAnswer:<\/p>\n

    \n
  1. When a candle is burnt both physical and chemical changes take place.<\/li>\n
  2. Burning of candle giving heat and light and reducing its size is a chemical change.<\/li>\n
  3. The wax melted during burning again condenses to solid wax is a physical change.<\/li>\n
  4. Part of the candle burnt is a permanent change and it cannot be reversed.<\/li>\n
  5. Due to the burning of the candle, carbon dioxide and water vapour are produced.<\/li>\n<\/ol>\n

    Examples:<\/p>\n

      \n
    1. Burning of LPG in our kitchen.<\/li>\n
    2. Liquid state of LPG in the cylinder is converted into gaseous state when comes out This is a physical change.<\/li>\n
    3. When LPG burns in air heat is produced, this is a chemical change.<\/li>\n<\/ol>\n

      Question 3.
      \nDefine crystallization.
      \nAnswer:
      \nThe process of separating a soluble solid from the solution by heating or evaporating is called crystallization.<\/p>\n

      Question 4.
      \nGuess the consequences of burning crackers during festivals and celebrations.
      \nAnswer:<\/p>\n

        \n
      1. Firing crackers during festivals and celebrations increase the concentration of dust and pollutants in the air.<\/li>\n
      2. The dust particles get settled on the surrounding surfaces which are packed with chemicals like copper, zinc, sodium and magnesium. They cause damage to paintings.<\/li>\n
      3. The quality of ambient air will be decreased drastically.<\/li>\n
      4. Firing of crackers causes lot of sound pollution.<\/li>\n
      5. The oxides of sulphur pollute the air and causes lung diseases to human beings.<\/li>\n
      6. The increase in levels of air pollutants cause acid rains, corrosion of objects and decrease in visibility.<\/li>\n<\/ol>\n

        Question 5.
        \nProve experimentally chemical change is a permanent change.
        \nAnswer:
        \n\"AP
        \nAim : To prove chemical change is a permanent change.<\/p>\n

        Materials required :
        \nMagnesium ribbon, water, match box, bunsen flame.<\/p>\n

        Procedure:
        \n1) Take a small piece of Magnesium ribbon.<\/p>\n

        2) Burn it on a flame we will find brilliant white dazzling light leaving a powdery substance behind.<\/p>\n

        3) This is because when magnesium burns in the presence of oxygen, it forms magnesium oxide in the form of powdered ash. This is a new substance.
        \nMagnesium + Oxygen \u2192 Magnesium Oxide (new substance)
        \nThis is a permanent change.<\/p>\n

        4) Now, take a small quantity of Magnesium oxide and mix it with a small quantity of water and dissolve it.
        \nMagnesium Oxide + Water \u2192 Magnesium Hydroxide (new substance)
        \nThis is also a permanent change.
        \nHere also another new substance is formed.<\/p>\n

        5) By testing this new substance with blue and red litmus papers. Red litmus turns blue. Then Magnesium Hydroxide is a base.<\/p>\n

        Inference :
        \nChanges that occur with the formation of new substance with different chemical Coposition or transformation of a substance into another substance with the evolution or absorption of heat; or light energy are termed as chemical changes. These are permanent changes.<\/p>\n

        \"AP<\/p>\n

        Question 6.
        \nGuess the reasons for increase of plastic pollution.
        \nAnswer:
        \nMain reasons for increase of plastic pollution :<\/p>\n

          \n
        1. Rising human population and their needs, people depend on plastic.<\/li>\n
        2. The food industry which packs everything on plastic.<\/li>\n
        3. Increase in usage of plastic bottles and container caps.<\/li>\n
        4. Indiscriminate usage of plastic bags and carriers.<\/li>\n
        5. Over usage of plastic straws and stirrers.<\/li>\n
        6. Lack of proper management of plastic waste.<\/li>\n
        7. Unawareness among the public about the hazardous affects of plastic wastes.<\/li>\n
        8. People are not following the 3’Rs (Recycle – Reduce – Reuse) method to reduce plastic wastes.<\/li>\n<\/ol>\n

          Question 7.
          \nHow can you appreciate the role of periodic changes in nature?
          \nAnswer:<\/p>\n

            \n
          1. Changes that are repeating at regular intervals of time are called as periodic changes.<\/li>\n
          2. Formation of day and night, for every 12 hours the sun rise and the sun set are repeating.<\/li>\n
          3. Seasons like summer, rainy, winter and spring occur every year at regular intervals.<\/li>\n
          4. The full moon and new moon repeats every month.<\/li>\n
          5. Heart beat of human beings takes place periodically.<\/li>\n
          6. Low and high tides in sea are periodic.<\/li>\n
          7. All these changes are periodically taking place in nature.<\/li>\n
          8. They provide us all comforts to live on this earth. I appreciate these periodic changes in nature for providing a happy life on this earth.<\/li>\n
          9. Without these changes in environment, life of us would become impossible.<\/li>\n<\/ol>\n

            Question 8.
            \nSuggest some methods to prevent rusting of iron articles.
            \nAnswer:<\/p>\n

              \n
            1. The problem of rusting of iron and other metal articles is common experience in almost every home.<\/li>\n
            2. It spoils beautiful articles and makes them look ugly.<\/li>\n
            3. The following are some of the ways to prevent the rusting of iron.
              \na) Do not allow the iron articles to come in direct contact with Oxygen in the air, water or both.
              \nb) Apply a coat of paint or grease on an iron article.<\/li>\n<\/ol>\n

              Question 9.
              \nRavi prepared carbon-dioxide using baking soda and vinegar. Carbon-dioxide changed lime water into milky white. Represent this experiment in a diagram with labelling.
              \nAnswer:
              \n\"AP
              \nPreparation of carbon dioxide<\/p>\n

              7th Class Science 10th Lesson Changes Around Us InText Questions and Answers<\/h3>\n

              7th Class Science Textbook Page No. 54<\/span><\/p>\n

              Question 1.
              \nWhat change do you observe after removing mehandi applied on your palms?
              \nAnswer:
              \nThe hands get red colour after removing mehandi.<\/p>\n

              Question 2.
              \nCan we clear the printed letters on paper. Why?
              \nAnswer:
              \nNo, it is a permanent change.<\/p>\n

              \"AP<\/p>\n

              Question 3.
              \nWater dispenser gives hot, normal and cold water. Is this natural or man made?
              \nAnswer:
              \nMan-made.<\/p>\n

              7th Class Science Textbook Page No. 55<\/span><\/p>\n

              Question 4.
              \nWhat is change?
              \nAnswer:
              \nAn act or process through which something becomes different.<\/p>\n

              Question 5.
              \nHow do we know that something has changed?
              \nAnswer:
              \nBy observing the changes in shape, size, colour and chemical properties.<\/p>\n

              Question 6.
              \nWhat are the possible reasons for that change?
              \nAnswer:
              \nThey may be because of physical or chemical changes.<\/p>\n

              Question 7.
              \nIs there any involvement of human beings?
              \nAnswer:
              \nNo, these are natural changes.<\/p>\n

              7th Class Science Textbook Page No. 56<\/span><\/p>\n

              Question 8.
              \nIs there any change in its shape?
              \nAnswer:
              \nYes, it\u2019s size will increase.<\/p>\n

              Question 9.
              \nHow does it happen?
              \nAnswer:
              \nThe air blown into the balloon occupies the space and the balloon becomes bigger in size. ,<\/p>\n

              Question 10.
              \nIs it by itself or by anybody else?
              \nAnswer:
              \nIt is a man made change.<\/p>\n

              \"AP<\/p>\n

              Question 11.
              \nSo what type of change it is?
              \nAnswer:
              \nThis is a man made change.<\/p>\n

              Question 12.
              \nHow much time they require?
              \nAnswer:
              \nThey require longer periods. It is a slow process.<\/p>\n

              7th Class Science Textbook Page No. 57<\/span><\/p>\n

              Question 13.
              \nHave you ever noticed the following changes in our daily life?
              \nAnswer:
              \nYes. It is also a reversible change.<\/p>\n

              7th Class Science Textbook Page No. 58<\/span><\/p>\n

              Question 14.
              \nDo the formed substance differs from original substance?
              \nAnswer:
              \nYes. The formed new substance is completely different.<\/p>\n

              Question 15.
              \nCan we get original substance by reversing the conditions?
              \nAnswer:
              \nNo.<\/p>\n

              7th Class Science Textbook Page No. 50<\/span><\/p>\n

              Question 16.
              \nHave you seen large crystals of sugar (Missrf) or crystal salt?
              \nAnswer:
              \nYes.<\/p>\n

              Question 17.
              \nDo you know how we get these crystals?
              \nAnswer:
              \nYes. We get them through crystallization.<\/p>\n

              Question 18.
              \nHave you ever observed the formation of small sugar crystals on sweets like Jilebi and badushah, which are kept aside for a long period?
              \nAnswer:
              \nYes.<\/p>\n

              \"AP<\/p>\n

              Question 19.
              \nWhat is the reason for this?
              \nAnswer:
              \nIt is because of crystallization.<\/p>\n

              Question 20.
              \nWhat changes do you notice at the end?
              \nAnswer:
              \nWe notice the formation of large size crystals of sugar at the bottom of the beaker.<\/p>\n

              Question 21.
              \nDo you find any crystals in the solution?
              \nAnswer:
              \nNo, we will find the crystals at the bottom of the beaker.<\/p>\n

              Question 22.
              \nWhat type of change it is?
              \nAnswer:
              \nIt is a physical change.<\/p>\n

              7th Class Science Textbook Page No. 62<\/span><\/p>\n

              Question 23.
              \nIn Which cases new substances are formed?
              \nAnswer:
              \nIn chemical changes, we get new substance.<\/p>\n

              Question 24.
              \nHave you observed rusting of iron, curdling of milk?
              \nAnswer:
              \nYes, I observed many times.<\/p>\n

              Question 25.
              \nDo we get the same substance after change? Is the change is temporary or permanent?
              \nAnswer:
              \nNo, it is a permanent change.<\/p>\n

              Question 26.
              \nDoes the ash formed look like Magnesium ribbon?
              \nAnswer:
              \nNo.<\/p>\n

              Question 27.
              \nDo you think the magnesium ribbon and the ash have the same composition?
              \nAnswer:
              \nNo<\/p>\n

              Question 28.
              \nWhat do you observe?
              \nAnswer:
              \nWe get Magnesium Hydroxide.<\/p>\n

              \"AP<\/p>\n

              Question 29.
              \nDo you observe any change in the state of the substance?
              \nAnswer:
              \nIt is in liquid state (from solid state)<\/p>\n

              Question 30.
              \nIs it an acid or base?
              \nAnswer:
              \nBase.<\/p>\n

              7th Class Science Textbook Page No. 63<\/span><\/p>\n

              Question 31.
              \nDid you observe iron nails, iron gates, iron benches or pieces of iron left in the open ground for a long time?
              \nAnswer:
              \nYes.<\/p>\n

              Question 32.
              \nDid you observe any change in colour?
              \nAnswer:
              \nWe can observe a brown colour layer on the surface of iron articles.<\/p>\n

              Question 33.
              \nHow can we protect the iron articles from rusting?
              \nAnswer:
              \nThrough a process called Galvanization.<\/p>\n

              7th Class Science Textbook Page No. 64<\/span><\/p>\n

              Question 34.
              \nAre there any other ways by which rusting of iron can be prevented?
              \nAnswer:
              \nWhen the iron articles are coated with metals like chromium or zinc, we can prevent them from rusting.<\/p>\n

              Question 35.
              \nHave you observed the handles of bicycles, metal rims of bicycle and motor cycles?
              \nAnswer:
              \nYes.<\/p>\n

              Question 36.
              \nDo these articles rust? If not why?
              \nAnswer:
              \nNo, because they are coated with zinc or chromium.<\/p>\n

              Question 37.
              \nWhat changes do you notice?
              \nAnswer:
              \nWe can notice a brown layer on their outer surface.<\/p>\n

              Question 38.
              \nCan you prevent the browning of cut vegetables and fruits?
              \nAnswer:
              \nYes.<\/p>\n

              Question 39.
              \nHave you observed your mother keeping the cut potatoes or brinjals in cold water?
              \nAnswer:
              \nYes.<\/p>\n

              7th Class Science Textbook Page No. 65<\/span><\/p>\n

              Question 40.
              \nIn which fruit or vegetable do you notice change in colour?
              \nAnswer:
              \nIn Apple, Brinjal and Potato.<\/p>\n

              Question 41.
              \nWhy does this change occurs?
              \nAnswer:
              \nBecause some vegetables and fruits react with oxygen in the air when they cut. Due to this oxidation process, brown layer is formed on the surface of these fruits and vegetables.<\/p>\n

              Think & Respond<\/span><\/p>\n

              Question 1.
              \nWhen food gets spoiled, it produces a foul smell. Shall we call this change as a chemical change?
              \nAnswer:
              \nWhen food gets spoiled by micro organisms, it produces a foul smell. By the action of the enzymes released by these microbes, the components of the food undergo chemical changes. Due to this, the food emits foul smell. It is a permanent change and irreversible in nature.<\/p>\n

              \"AP<\/p>\n

              Question 2.
              \nYou know that plants produce their food by a process called photosynthesis. Can we call photosynthesis a chemical change?
              \nAnswer:
              \nPhotosynthesis is a chemical change. Here, carbondioxide is reduced to glucose. In this process oxygen is evolved. It is a permanent and irreversible change. New substance are formed.<\/p>\n

              Question 3.
              \nDo all the materials react with oxygen in the air?
              \nAnswer:
              \nNo.<\/p>\n

              Question 4.
              \nObserve Gold and Silver. You wear them in the form of ornaments. Even if they get exposed to air for long time, they do not change their colour. Why?
              \nAnswer:
              \nMetals like gold and silver, even if they are exposed to air for a long time, they do not change colour or get rusted.<\/p>\n

              It means that they are resistant to corrosion which is the reason why we use them in making ornaments.<\/p>\n

              Activities and Projects<\/span><\/p>\n

              Question 1.
              \nCollect information on the process of artificial ripening of fruits in fruit market and discuss whether it is useful or harmful.
              \nAnswer:<\/p>\n

                \n
              1. Calcium carbide more commonly known as “masala” is used for artificial ripening of fruits. It is very harmful to health.<\/li>\n
              2. Calcium carbide is a carcinogenic agent.<\/li>\n
              3. The most important precaution to avoid eating such artificially ripened fruits is to go in for fruits and vegetables which are not unseasonal.<\/li>\n
              4. Always wash the vegetables and fruits properly before consuming.<\/li>\n<\/ol>\n

                Question 2.
                \nWhen you burn a piece of wood different changes take place analyse the following. Predict possible changes and list them all.
                \na) Are there any physical changes among them?
                \nb) How many forms of energy are released in the change?
                \nc) What chemical changes do you notice?
                \nd) Explain briefly why these occur.
                \nAnswer:
                \na) No physical changes is observed.
                \nb) The energy is released in the form of heat sound and light energy.
                \nc) When a piece of wood is burnt a new material is formed (ash). We also notice change in shape and size of new materials (powder). This type of change which leads to form new substance is called chemical changes.
                \nd) Wood turns into carbondioxide and ash
                \nCarbon (Wood) + Oxygen (Air) \u2192 CO2<\/sub> + Ash<\/p>\n

                Activities<\/span><\/p>\n

                Activity – 1<\/span><\/p>\n

                Question 1.
                \nWhat changes do you observe, When a balloon is blown?
                \nAnswer:
                \nChange in the shape of balloon is done by blowing air into it. This is a man made change. When we left off the air from it, it returns to its normal shape. This is a physical change and reversible one.<\/p>\n

                Activity – 2<\/span><\/p>\n

                Question 2.
                \nObserve the changes mentioned in the following table and complete it.<\/p>\n\n\n\n\n\n\n\n\n
                Change<\/td>\nTime taken
                \nshorter\/longer duration<\/td>\n                		Type of change
                \nFast\/ Slow<\/td>\n<\/tr>\n
                1. Digestion of food<\/td>\n<\/td>\n<\/td>\n<\/tr>\n
                2. Burning a small candle<\/td>\n<\/td>\n<\/td>\n<\/tr>\n
                3. Occurrence of lightening<\/td>\n<\/td>\n<\/td>\n<\/tr>\n
                4. Construction of Dam<\/td>\n<\/td>\n<\/td>\n<\/tr>\n
                5. Rusting of iron<\/td>\n<\/td>\n<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

                Answer:<\/p>\n\n\n\n\n\n\n\n\n
                Change<\/td>\nTime taken
                \nshorter\/longer duration<\/td>\n                		Type of change
                \nFast\/ Slow<\/td>\n<\/tr>\n
                1. Digestion of food<\/td>\nLonger duration<\/td>\nSlow<\/td>\n<\/tr>\n
                2. Burning a small candle<\/td>\nShorter<\/td>\nFast<\/td>\n<\/tr>\n
                3. Occurrence of lightening<\/td>\nShorter<\/td>\nFast<\/td>\n<\/tr>\n
                4. Construction of Dam<\/td>\nLonger duration<\/td>\nSlow<\/td>\n<\/tr>\n
                5. Rusting of iron<\/td>\nLonger duration<\/td>\nSlow<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

                Activity – 3<\/span><\/p>\n

                Question 3.
                \nWhat changes do you notice when few pieces of ice in a beaker are heated? What do you mean by a physical change? Before heating After heating After freezing
                \nAnswer:
                \n\"AP<\/p>\n

                  \n
                1. Take few pieces of ice in a beaker and heat them on burner as shown in the figure.<\/li>\n
                2. We notice that ice slowly melts and becomes water and on further heating it changes to steam.<\/li>\n
                3. If we reduce the temperature, the water vapour changes back to water and when temperature is further reduced it changes to ice.<\/li>\n
                4. In the above activity we notice the change of the state of ice to water and to vapour but the substance, water, remains the same.<\/li>\n
                5. Changes of this type where no new substance is formed are known as physical changes.<\/li>\n
                6. When a material undergoes a change in shape, size, colour or state it is called a Physical Change.<\/li>\n
                7. Generally, no new substance is formed in a physical change.<\/li>\n<\/ol>\n

                  Activity – 4<\/span><\/p>\n

                  Question 4.
                  \nDescribe how do you perform the activity to observe the reaction of vinegar with baking soda?
                  \nAnswer:
                  \n\"AP<\/p>\n

                    \n
                  1. First set up the apparatus as shown in Fig.<\/li>\n
                  2. Take a teaspoon of vinegar (acetic acid) in a test tube and add a pinch of baking soda (Sodium bicarbonate) to it.<\/li>\n
                  3. You observe bubbles coming out with a hissing sound. Pass this gas through freshly prepared Limewater (Calcium Hydroxide).<\/li>\n
                  4. Limewater changes to milky white showing that the gas sent into the test tube is Carbon dioxide.<\/li>\n
                  5. Vinegar + Baking Soda \u2192 Sodium acetate + Carbon dioxide + Water<\/li>\n
                  6. Carbon dioxide + Lime Water \u2192 Calcium Carbonate + Water<\/li>\n
                  7. In these reactions the new substances like Carbon dioxide and Calcium Carbonate are formed. Hence it is a chemical change.<\/li>\n
                  8. When a material undergoes a change in its composition it is called a chemical change.<\/li>\n<\/ol>\n

                    \"AP<\/p>\n

                    Activity – 5<\/span><\/p>\n

                    Question 5.
                    \nWrite the approximate time after which they repeat.<\/p>\n\n\n\n\n\n\n\n\n
                    Natural<\/td>\nPeriod of time of repetetion (Approximate)<\/td>\n<\/tr>\n
                    1. Change of day and night<\/td>\nEvery 12 hours<\/td>\n<\/tr>\n
                    2. Withering of leaves<\/td>\n<\/td>\n<\/tr>\n
                    3. Rising of the pole star<\/td>\n<\/td>\n<\/tr>\n
                    4. Change of Seasons<\/td>\n<\/td>\n<\/tr>\n
                    5. Appearance of full moon<\/td>\n<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

                    Answer:<\/p>\n\n\n\n\n\n\n\n\n
                    Natural<\/td>\nPeriod of time of repetetion (Approximate)<\/td>\n<\/tr>\n
                    1. Change of day and night<\/td>\nEvery 12 hours<\/td>\n<\/tr>\n
                    2. Withering of leaves<\/td>\n1 year<\/td>\n<\/tr>\n
                    3. Rising of the pole star<\/td>\n24 hours<\/td>\n<\/tr>\n
                    4. Change of Seasons<\/td>\n1 year<\/td>\n<\/tr>\n
                    5. Appearance of full moon<\/td>\n30 days<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

                    Activity – 6<\/span><\/p>\n

                    Question 6.
                    \nHow do you produce large size of sugar crystals ? What type of change is it?
                    \nAnswer:
                    \n\"AP<\/p>\n

                      \n
                    1. Take a big size test tube. Fill half of it with water. Add some sugar to it and stir it.<\/li>\n
                    2. Keep adding sugar and stirring until saturation is attained.<\/li>\n
                    3. Then heat this sugar solution and add some more sugar to it while stirring continuously.<\/li>\n
                    4. Continue adding sugar till no more sugar can be dissolved in it.<\/li>\n
                    5. Now filter the solution and allow it cool for half an hour.<\/li>\n
                    6. We notice formation of large size crystals of sugar at the bottom of the beaker. Thus the small granules of sugar added changed into large size sugar crystals.<\/li>\n
                    7. This is a physical change.<\/li>\n<\/ol>\n

                      Activity – 7<\/span><\/p>\n

                      Question 7.
                      \nSome changes are given in the table. Write possible changes you notice for each case and put (\u2713) in the appropriate column.
                      \nAnswer:
                      \n\"AP<\/p>\n

                      1) In the above activity we notice that only in some examples like burning of paper, burning of crackers, change of milk to curd, boiling of egg, etc., a new substance is formed.<\/p>\n

                      2) But in other examples of changes we notice an change in state or colour or size or shape etc but the substance remains same and no new substance is formed.<\/p>\n

                      Activity – 9<\/span><\/p>\n

                      Question 9.
                      \nComplete the following table.<\/p>\n\n\n\n\n\n\n\n\n\n\n
                      Name of the Fruit<\/td>\nWhether turned brown or not<\/td>\n<\/tr>\n
                      Yes<\/td>\nNo<\/td>\n<\/tr>\n
                      1. Apple<\/td>\n<\/td>\n<\/td>\n<\/tr>\n
                      2. Brinjal<\/td>\n<\/td>\n<\/td>\n<\/tr>\n
                      3. Potato<\/td>\n<\/td>\n<\/td>\n<\/tr>\n
                      4. Tomato<\/td>\n<\/td>\n<\/td>\n<\/tr>\n
                      5. Cucumber<\/td>\n<\/td>\n<\/td>\n<\/tr>\n
                      6. Mango<\/td>\n<\/td>\n<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

                      Answer:<\/p>\n\n\n\n\n\n\n\n\n\n\n
                      Name of the Fruit<\/td>\nWhether turned brown or not<\/td>\n<\/tr>\n
                      Yes<\/td>\nNo<\/td>\n<\/tr>\n
                      1. Apple<\/td>\n\u2713<\/td>\n<\/td>\n<\/tr>\n
                      2. Brinjal<\/td>\n\u2713<\/td>\n<\/td>\n<\/tr>\n
                      3. Potato<\/td>\n\u2713<\/td>\n<\/td>\n<\/tr>\n
                      4. Tomato<\/td>\n<\/td>\n\u2713<\/td>\n<\/tr>\n
                      5. Cucumber<\/td>\n<\/td>\n\u2713<\/td>\n<\/tr>\n
                      6. Mango<\/td>\n<\/td>\n\u2713<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

                      Some fruits and vegetables when cut, react with oxygen in the air. The process of reaction with oxygen is called oxidation. Due to this process brown layer is formed on the surface of fruits and vegetables.<\/p>\n","protected":false},"excerpt":{"rendered":"

                      SCERT AP 7th Class Science Study Material Pdf 10th Lesson Changes Around Us Textbook Questions and Answers. AP State Syllabus 7th Class Science 10th Lesson Questions and Answers Changes Around Us 7th Class Science 10th Lesson Changes Around Us Textbook Questions and Answers Improve Your Learning I. Fill in the blanks. 1. Changes in which … Read more<\/a><\/p>\n","protected":false},"author":5,"featured_media":37913,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"spay_email":""},"categories":[9],"tags":[],"jetpack_featured_media_url":"https:\/\/apboardsolutions.com\/wp-content\/uploads\/2022\/02\/10th-Lesson-Changes-Around-Us.png","_links":{"self":[{"href":"https:\/\/apboardsolutions.com\/wp-json\/wp\/v2\/posts\/17094"}],"collection":[{"href":"https:\/\/apboardsolutions.com\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/apboardsolutions.com\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/apboardsolutions.com\/wp-json\/wp\/v2\/users\/5"}],"replies":[{"embeddable":true,"href":"https:\/\/apboardsolutions.com\/wp-json\/wp\/v2\/comments?post=17094"}],"version-history":[{"count":1,"href":"https:\/\/apboardsolutions.com\/wp-json\/wp\/v2\/posts\/17094\/revisions"}],"predecessor-version":[{"id":17095,"href":"https:\/\/apboardsolutions.com\/wp-json\/wp\/v2\/posts\/17094\/revisions\/17095"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/apboardsolutions.com\/wp-json\/wp\/v2\/media\/37913"}],"wp:attachment":[{"href":"https:\/\/apboardsolutions.com\/wp-json\/wp\/v2\/media?parent=17094"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/apboardsolutions.com\/wp-json\/wp\/v2\/categories?post=17094"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/apboardsolutions.com\/wp-json\/wp\/v2\/tags?post=17094"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}