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Write a scientific reason.
The non-metallic character increases while going from left to right in a period.
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Define acceleration due to gravity.
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Write the acceleration due to gravity value on the surface of Earth.
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The mass of planet ‘X’ is four times that of the earth, and its radius is double the radius of the earth. The escape velocity of a body from the earth is 11.2 × 103 m/s. Find the escape velocity of a body from the planet ‘X’.
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Distinguish between Direct current and alternating current.
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Explain the following reaction with an example.
Esterification
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Explain the following reaction with an example.
Saponification
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Give a chemical reaction in which a catalyst is used.
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Write the characteristics of ethanoic acid.
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Distinguish between:
Universal gravitational constant – Gravitational acceleration of earth.
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Write a short note.
Escape Velocity
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The mass and weight of an object on earth are 5 kg and 49 N respectively. What will be their values on the moon? Assume that the acceleration due to gravity on the moon is 1/6th of that on the earth.
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3, 1, 2 electrons are in valence shells of X, Y, Z elements resp. From this information, write the name of the groups it belongs to and its valency.
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Read the given passage carefully and answer the questions.
| We know that the force of gravity due to the earth acts on each and every object. When we were holding the stone in our hand, the stone was experiencing this force, but it was balanced by a force that we were applying on it in the opposite direction. As a result, the stone remained at rest. Once we release the stone from our hands, the only force that acts on it is the gravitational force of the earth and the stone falls down under its influence. Whenever an object moves under the influence of the force of gravity alone, it is said to be falling freely. Thus the released stone is in a free fall. In free fall, the initial velocity of the object is zero and goes on increasing due to the acceleration due to the gravity of the earth. During free fall, the frictional force due to air opposes the motion of the object and a buoyant force also acts on the object. Thus, true free fall is possible only in a vacuum. |
- Complete the following statement by choosing the right option.
The stone held in the hand is stable because on it ......- two unbalanced forces are exerted.
- only the gravitational force of the earth is exerted.
- gravitational force of the earth is not exerted.
- two balanced forces are exerted.
- Why does free fall not happen on the earth?
- Why does the velocity of the object increase during the free fall?
- Which type of force exerts on the object during free fall?
- Why does free fall happen only in a vacuum?
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Observe the figure and write the answers to the following questions.
- Write the name of the reaction shown in the following figure.
- Write the above chemical reaction in the form of a balanced equation.
- Write the name of the product produced in the above reaction, write a use.
- Write the name of the catalyst used in the above reaction.
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In the presence of the acid catalyst, ethanoic acid reacts with ethanol and ______ ester is produced.
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Answer the following questions based on the given graph.
- Identify which curve shows AC and DC.
- What is the frequency of AC and DC?
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The reaction between acetic acid and sodium carbonate is shown in the following figure.
Answer the questions with the help of a diagram.
- Which gas does come out as effervescence in the big test tube?
- What is the colour change in the lime water present in the small test tube?
- Write the related reaction.
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