Answer:

Explanation:
Data provided as per the question below:-
Wavelength = 430.nm
The computation of the frequency of the light is shown below:-
Frequency = Velocity of light ÷ Wavelength
The Velocity of light = 
Wavelength = 430 nm =
m
Frequency = 


= 
Therefore for determining the frequency we simply applied the above formula.
Drying clothes is a physical change, because it is not permanent. The clothes could just be wettened again, therefore it is not a chemical change.
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Answer:
aqueous acid is used as a reagent.
Explanation:
Addition of Grignard reagent in aldehyde and followed by the acidification give rise to the primary or secondary alcohol. when the formaldehyde is used than the primary alcohol is formed otherwise secondary alcohol is formed.
in this reaction we also use the aqueous acid for the acidification as a reagent. We add aqueous acid when ethanol is present. This is because ethanol is get converted in the presence of aqueous acid into the chloroethane.
Magnetizing steel is a physical change, not a chemical change.
Salt dissolving in a glass of water, using electricity to break down water into hydrogen and oxygen, rust forming on an iron fence and gas burning on a stove.