Tag: phenomena around us

Questions Related to phenomena around us

Halley's comet revolves around the sun once in every 76 Years. This is a:

chemistry phenomena around us changes and its classification types of changes classification of changes

  1. photochemical change

  2. periodic change

  3. chemical change

  4. irreversible change

Show answer
Correct Option: B
Explanation:

It is a periodic change $-$ because changes that occur after a fix interval of time is known as periodic change.

Here periodic change in $76$ years
photochemical change is due to light chemical change $-$ where reactant react to produce products.

Which of the following is not considered a temperature scale? 

chemistry phenomena around us changes and its classification types of changes classification of changes

  1. Fahrenheit

  2. Kelvin

  3. Calorie

  4. Celsius

Show answer
Correct Option: C
Explanation:

Calorie is used to measure the amount of energy needed to raise the temperature of one gram/kilogram  of a substance like water by one degree.

Iron pipes coated with zinc do not get rusted easily.

chemistry phenomena around us changes and its classification types of changes classification of changes

  1. True

  2. False

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Correct Option: A
Explanation:

It is true.

Coating iron with zinc is known as galvanizing. Iron metals get rusted when in contact with oxygen and moisture (air).
If coated with zinc, no interaction between oxygen and iron is there and hence the pipe does not get rusted easily.

When an iron nail is added to acidic copper sulphate solution, the colour of the deposit on the iron nail is:

chemistry phenomena around us changes and its classification types of changes classification of changes

  1. brown

  2. blue

  3. green

  4. pink

Show answer
Correct Option: A
Explanation:

When a nail is added to acidic copper sulphate solution, the color of the deposit on the iron nail is brown. Copper sulphate reacts with iron to form iron sulphate and copper. Brown colored copper deposits on nail.

A change in which a substance undergoes changes in its physical properties is called:

chemistry phenomena around us changes and its classification types of changes classification of changes

  1. chemical change

  2. physical change

  3. no change

  4. biological change

Show answer
Correct Option: B
Explanation:

A change in which a substance changes its physical properties like appearance, texture, colour, odour, melting points, boiling points, density, solubility, polarity etc... are called physical changes. 


Physical properties can be observed or measured without changing the composition of matter. They are used to observe and describe matter.

Hence, the correct option is $\text{B}$

When substance cool off, there is a decrease in:

chemistry phenomena around us changes and its classification types of changes classification of changes

  1. size of substance

  2. vibrations of the molecules

  3. temperature

  4. all of the above

Show answer
Correct Option: D
Explanation:

When a substance cools off, the size of substance, vibrations, a temperature of the substance decreases, as the heat is dissipated out resulting in the decrease in the size of the substance, and the internal vibrations between the molecules also decrease as the temperature decreases, due to the loss of heat.

A metal ball which is passing through metal ring will not pass after :

chemistry phenomena around us changes and its classification types of changes classification of changes

  1. heating

  2. freezing

  3. constant conditions

  4. refrigerating

Show answer
Correct Option: A
Explanation:

All metals have a property of expansion when heated. Since the metal ball is heated, it will expand and will not pass the ring now.


Thus heating is the correct answer.

Hence the option A is correct.

Things or processes which cannot be reversed are called

chemistry phenomena around us changes and its classification types of changes classification of changes

  1. Irreversible process

  2. Reversible process

  3. Cyclic process

  4. None of the above

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Correct Option: A
Explanation:

Things or processes which cannot be reversed are called irreversible process Burning of coal is irreversible as it will not produce coal again.

Which of the following processes prevents iron from rust?

chemistry phenomena around us changes and its classification types of changes classification of changes

  1. Galvanization

  2. Painting

  3. Both a and b

  4. None of the above

Show answer
Correct Option: C
Explanation:

Galvanization(Coating of non-reactive metal on iron) and painting prevents iron to get in contact with moisture thus prevent it from rusting. 


Hence, option C is correct.

Permanent change is a :

chemistry phenomena around us changes and its classification types of changes classification of changes

  1. Physical change

  2. Chemical change

  3. Both physical and chemical change

  4. None of the above

Show answer
Correct Option: B
Explanation:

A chemical change is permanent. A new substance is formed.


Forms of energy, such as heat, light or electricity, may be emitted or absorbed during a chemical reaction. A chemical change is generally irreversible.

Hence option B is correct.