As a fire extinguisher carbon di-oxide is used in case of electrical or other fire accidents. Why $C{O}_2$ is used?

Consider the following statements: If there were no phenomenon of capillarity: 

1. It would be difficult to use a kerosene lamp.
2. One would not be able to use a straw to consume a soft drink.
3. The blotting paper would fail to function.
4. The big trees that we see around would not have grown on the Earth.

Which of the statements given above are correct?

Which of the following statements is/are INCORRECT?

1. A sugar solution is a homogenous mixture.
2. Both homogenous and heterogeneous mixtures can be separated through physical methods only.
3. Compounds can be separated through chemical methods but not through physical methods.

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Which of the following is/are an example of corrosion?

1. Copper reacts with moist carbon dioxide in the air.
2. Silver articles when exposed to air.
3. Iron when exposed to moist air.

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Mercury is used in-

1. Mascara
2. Dental restoration
3. Ornaments

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Which of the following statements are correct?

1. Cathode rays will travel in a straight line if there is no electrical and magnetic field.
2. Cathode rays do not depend upon the material of electrodes.
3. Cathode rays depend upon the nature of the gas present in the cathode ray tube.

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