Answer:
Reason Down below
Explanation:
It is important because when you make observation you get a clue sometimes and it reactants i feel like it also takes places with observation. :)
<u>Answer:</u> D. the ionic compound calcium fluoride 
The correct option here is the fourth one.
<u>Explanation:</u>
Salt like compounds addition to water is likely to be inducing certain changes in temperature of freezing into solid and also alter the temperature of boiling.
It is noticed that addition of salts in water mostly tends to get lower the freezing temperatures from the original freezing point of water and among the given 3 options calcium fluoride tends to lower the freezing point most when compared to others.
Thus as vant hoff factor is highest factor for
and the freezing point will be lowest.
Answer: Parts per million (ppm)
Explanation:
Consider the units milligram per milliliter. This gives us one part of the solute per one million parts of solvent. That is 10^ -3/10^-3= 10^-6. This unit is commonly used in analytical chemistry to show very small concentration of analyte. A similar unit is parts per billion(ppb)