Mix Example - IMPROVEMENT IN FOOD RESOURCES Questions in English

Ravjot's mother always squeezes water from wet clothes in the spinner of a washing machine and then uses it to clean the floor:
$(a)$ Write the principle of the technique used in the above-mentioned process.
$(b)$ Write one more application of this technique.
$(c)$ What do you learn from Ravjot's mother?

The milkman in our society started carrying a lactometer. His move was well appreciated by the society members.
$(a)$ What is the use of a lactometer? On what principle does it work?
$(b)$ What values of the milkman are shown by this move?

Dalton was the first scientist to use symbols for elements. Chemical symbols act as a vocabulary of chemical language. Chemical symbols are used to describe chemical changes with clarity and precision. Chemical symbols help in identifying specific elements. Chemical symbols also represent an atom of a particular element. Chemical symbols also signify the atomic mass of an element.
$(a)$ How do symbols help in identifying specific elements?
$(b)$ How do we use symbols in daily life for our convenience?
$(c)$ What values do you find in using symbols?

During class,Ravi's teacher was teaching about Thomson's model of an atom,stating that an atom is electrically neutral,i.e.,it contains equal positive and negative charges,and that an atom consists of a sphere of positive charge in which electrons are embedded like plums in a pudding. Ravi wondered how his teacher related Thomson's model of an atom to a plum pudding,and he imagined that just as dry fruits are embedded in a Christmas pudding,electrons are embedded in a sphere of positive charge.
$(a)$ According to you,what kind of qualities does Ravi possess?
$(b)$ What are the limitations of Thomson's model?

After combing his hair,Sameer kept the comb on the table where some pieces of paper were lying. He observed that the plastic comb attracted small pieces of paper. He was surprised to see this and asked his teacher about it. His teacher explained to Sameer that matter contains charged particles and that an electrically charged object can attract an uncharged object. Specifically,upon rubbing with dry hair,a comb acquires an electric charge,which then attracts the pieces of paper.
$(a)$ Give any other practical application of this.
$(b)$ What kind of qualities are shown by Sameer?

Simran and Ria were enjoying dancing in the rain. Suddenly, a question struck Ria's mind: "How does rain fall on Earth?" To this, her elder sister Simran explained the water cycle: how clouds are formed when water evaporates due to the heating of water bodies, rises, expands, and cools to form tiny droplets that grow larger to form clouds, which then sprinkle rainwater onto the Earth. Simran also told Ria that this rainwater is essential and precious and must be conserved.
$(a)$ Which values are displayed by Simran?
$(b)$ Why is water conservation necessary?

Raman lives in a coastal village. He is the son of a fisherman. Whenever any unwanted animal comes in the net,instead of killing it,he puts it back in the sea.
$(a)$ What would have happened,had he killed those animals?
$(b)$ Give one reason to justify that Raman's action is environment-friendly.
$(c)$ How can you contribute to the preservation of flora and fauna around you? Mention any two steps.

In winter, in the industrialised and metro cities, especially in the morning hours, the visibility is greatly lowered due to the formation of a dark fog, generally resulting in serious road accidents. It also causes suffocation.
$(a)$ What does this indicate and also name this phenomenon?
$(b)$ How is this phenomenon produced? Name two gases which cause acid rain.

Kanchan purchased gold from a jeweller. She was,however,very apprehensive about the purity of the gold purchased by her. Ultimately,she approached a person who claimed he could test its purity by making certain measurements of weight of the gold in air and water.
$(a)$ What principle was he making use of for testing purity?
$(b)$ Write the relation by which he found the relevant quantity.
$(c)$ What value did Kanchan imbibe?

Chemical formula of a compound is a symbolic representation of its composition. We should know the following points to write the chemical formulae of chemical compounds:
$(i)$ Symbols of the combining elements.
$(ii)$ Valency of the combining elements.
In order to know the valency,we must calculate the valence electrons present in the atoms.
The electrons present in the outermost shell or valence shell are called valence electrons. The number of electrons in the atoms of some elements are given below. The elements which have one valency are called monovalent.
$(a)$ What is a chemical formula?
$(b)$ Which main points we must know to write the chemical formula of compounds?
$(c)$ Which values do we find associated with the use of formula for various things in daily life?

The number of dengue cases has increased in Sana's village in the last one year. She read in her textbook that diseases like dengue spread through mosquitoes which breed in stagnant water. She immediately suggested to her friends that they should kill the mosquitoes in water bodies in the locality. They also took the help of the nearest municipal office.
$(a)$ Which preventive measures do you suggest for the prevention of such diseases caused by mosquitoes? Mention any two measures.
$(b)$ Which values are displayed by Sana in taking this initiative?
$(c)$ Suggest one school activity to promote such values in school students.

Kavita,the science teacher,was teaching her students about the types of diseases based on duration: acute and chronic diseases. She also discussed their ability to spread in public and their immediate causes.
$(a)$ What are acute and chronic diseases? Give one example of each.
$(b)$ Name the type of diseases which spread by coming in contact with a sick person. Name the different types of organisms which cause diseases.

Sahil's grandfather had a prostate problem. The doctor advised him to go in for an ultrasound. Sahil accompanied his grandfather to a diagnostic centre. His grandfather went through the process and was given a photograph.
$(a)$ What is the principle of ultrasound? What waves are used for this purpose?
$(b)$ Name four other areas in which the ultrasound is used as a diagnostic tool.
$(c)$ What value did Sahil imbibe about ultrasound?

Ram tried hard to push the wall of a room. In the process of pushing the wall,he begins to perspire and feels exhausted although the wall does not move. Ram feels that he has done a lot of work and spent a lot of energy. Do you think that Ram was justified in making the statement that he has done a lot of work? Justify your answer and give the conditions under which work is done.

Rajan and his family members were going to Dalhousie in a car to enjoy their weekly holidays. While on the way,it started raining. During the journey,Rajan observed that when another vehicle or bus passed them and honked,the intensity of the sound produced was higher than it would be in an area without rain.
$(a)$ What,according to you,is the reason behind the increase in the intensity of sound during rain?
$(b)$ What value do you attribute to Rajan's observation?

Raman along with his family visited the Dead Sea. There,his father observed a lady lying on her back in the sea and reading a newspaper. This astonished Raman's father,who thought the lady might be practicing black magic. Raman explained to his father why the lady was not drowning.
$(a)$ What,according to you,is the reason the lady is not drowning in the Dead Sea?
$(b)$ What value is exhibited by Raman?

Gautam visited a fair along with his classmates. There he found that a hawker was selling balloons filled with helium gas. His teacher told the students that the balloons will rise in the sky and then stop after some distance. Gautam questioned his teacher as to why the balloons would stop. He started arguing with his teacher that the balloons would rise indefinitely. His teacher got irritated with him. Just then,Gautam's friend Avdesh took him aside and explained to him that the teacher was correct. The explanation given by Avdesh satisfied Gautam.
$(a)$ Why will the balloon stop after rising to a certain height?
$(b)$ What values are shown by Avdesh and Gautam?

On a voyage in their yacht,John and his father came across an iceberg. John advised his father to keep away from the iceberg. His father said that it is just a small piece of ice jutting out of the sea and there is nothing to bother. John told his father that icebergs are dangerous and narrated the story of the ship $Titanic$,which was sunk by an iceberg. John explained to his father why the iceberg was dangerous. This convinced his father,and they steered clear of the iceberg.
$(a)$ Why are icebergs in the sea dangerous?
$(b)$ What values are possessed by John and his father?

Vividha told Vasudha that she will show her some magic. Vividha took a metallic pipe. She asked Vasudha to hold one of its ends close to her ears. She gently tapped the other end of the pipe with a metallic object. She asked Vasudha what she heard. Vasudha said she heard two sounds.
$(a)$ Was this magic? Why did Vasudha hear two sounds?
$(b)$ What values are imbibed by Vividha?

Nakul was shooting his arrows towards a target. Every time the arrow fell short of the target. This annoyed him. His brother, Arjun, came to his rescue. He showed his brother the right way to shoot an arrow. When Nakul tried again, he found that the arrows started hitting the target.
$(a)$ What do you think Arjun might have told Nakul?
$(b)$ What are the values imbibed by Arjun?

Suhasini's uncle was advised by his doctor to have an ultrasound scan of his abdomen. Her uncle did not know much about the details and significance of this test. He also felt that it was too expensive and thought of postponing it. When Suhasini learnt about her uncle's problems,she immediately decided to do something about it. She took the help of her family,friends and neighbours and arranged for the cost of the test. She also told her uncle that an ultrasound scan of his abdomen would enable the doctors to know of the condition of his kidneys without causing any (test related) harm to him. This test was expensive because of its set-up that needed an expensive apparatus.
Her uncle was convinced and had the required ultrasound scan of his abdomen done. The resulting information greatly helped his doctor to treat him well.
$(a)$ What according to you,are the values displayed by Suhasini and her family,friends and neighbours to help her uncle?
$(b)$ What type of wave is used in an ultrasound scan?