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प्रश्न
Photosynthesis is a natural process by which green plants manufacture food in the presence of sunlight.
Can the change be reversed or is it irreversible?
उत्तर
The change cannot be reversed. It is irreversible.
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संबंधित प्रश्न
Give two reasons to justify water at room temperature is a liquid.
Tick (√) the correct alternative from the choice given for the following statement.
When we add water to the following substances, which one will show a chemical change?
Tick the most appropriate answer.
Chemical changes involve
The boiling point of water is 100° C. Express this in SI units (Kelvin scale).
Convert the temperature of 573 K to the Celsius scale.
Fill in the following blank with suitable words :
Temp on Kelvin scale = Temp on Celsius scale + ........................
Define 'melting point' of a substance ? What is the melting point of ice
What is sublimation ? Name two substances (other than ammonium chloride) which undergo sublimation.
Draw a labelled diagram of the experimental set-up to demonstrate the sublimation of ammonium chloride.
If the temperature of an object is 268 K, it will be equivalent to :
The latent heat of fusion of ice is :
Which one of the following set of phenomena would increase on raising the temperature ?
Define the following terms: Diffusion
Differentiate between: Miscible and immiscible liquids.
Give two examples of the following:
Substances which do not change their states.
State which of the following statement is true or false. If false write the correct statement.
Atoms/molecules in gases move only about their own positions.
Fill in the blanks with the correct word/s from the bracket.
Ice on absorption of heat converts to ‘X’ a process called ____ [vaporization / melting]. ‘X’ changes to water vapour on ____ [heating / cooling]. Water vapour changes back to ‘X’ on ____ [freezing / condensation]. The constant temperature at which ice changes into ‘X’ is called its ____ [fusion point / melting point / boiling point].
State if the following is a physical property of a substance.
Water acidified with dilute sulphuric acid is a good conductor of electricity.
Fill in the blank with the correct word of the statement given below:
Sublimation is _______ a change of state of matter.
What is inter-conversion of matter. Give the meaning of the terms involved in inter-conversion of matter
(a) Melting
(b) Vaporisation
(c) Liquefaction or condensation,
(d) Solidification or freezing
(e) Sublimation.
