How can the hair growth rate be used to determine how long ago an individual dyed their hair?

Hair grows 1cm each month, so take how many centimeter's the dyed hair is from the root and however cm's that is equals how many months ago someone dyed their hair.

Explanation:

Example: the dye begins 6cm from the root.  1cm = 1 month so that means that it has been 6 months since the individual dyed their hair.

idk what the options are but

these is a strong electrostatic attraction between the ions hence a lot of energy is needed to overcome this attraction

this is why the boiling points are so high