Answer:
1.3636
Explanation:
Write the expression for the refractive index.
n=c/v
c= speed of light in air
v= speed of light in material
=(3×10^8 m/s)/(2.2×10^8 m/s)
=1.3636
Answer: two waves with identical crests and troughs meet
Explanation:
My teacher gave me the answer
If iodine is added to a starch solution, they react with each other and the iodine darkens to an almost pitch black.
however, if iodine is added to a solution containing no starch, it will show up only as an extremely pale brown. almost colorless and hardly visible.
when following the changes in some inorganic oxidation reduction reactions, iodine may be used as an indicator to follow the changes of iodide ion and iodine element. soluble starch solution is added. only iodine element in the presence of iodide ion will give the characteristic blue black color. neither iodine element alone nor iodide ions alone will give the color result.
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Answer: The chemical formula for the compound of these two elements is 
Explanation:
For formation of a neutral ionic compound, the charges on cation and anion must be balanced. The cation is formed by loss of electrons by metals and anions are formed by gain of electrons by non metals.
Here metal lead is having an oxidation state of +4 called as
cation and sulphur non metal has oxidation state of -2 called as
. Thus they combine and their oxidation states are exchanged and written in simplest whole number ratios to give neutral 
The chemical formula for the compound of these two elements is 
Answer:
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Explanation: