Answer:
A
Explanation:
The answer to this question is A. Both ripening and spoiling are chemical reactions.
Spoiling is a chemical reaction because spoiled food has bad smell and taste and it changes colour too.
Ripening of fruits is a chemical change. For example the colour could change as well as the texture.
Answer: On increasing temperature at which adsorption is carried out decreases the extent of physisorption.
Explanation:
An adsorption where molecules of the adsorbate are placed or held on the surface of adsorbent by Vander waals forces is called physisorption.
There is basically physical bonding between the molecules of gas to the surface of a solid or liquid.
Physisorption is reversible in nature and occurs at low temperatures.
It is not specific in nature which means that all gases are adsorbed on the surface of every solid substance to some extent.
Thus, we can conclude that on increasing temperature at which adsorption is carried out decreases the extent of physisorption.
The sample of smoke described above can be described as a heterogeneous mixture. This type of mixture do not have uniform properties and composition. So, getting a certain small sample would not represent the whole mixture since it does not have uniform composition.
Nickel is a pure substance
Rust is also a pure substance