A conductor is what helps heat or electricity pass through an object. Examples of conductors are, silver, iron, aluminum, etc..
An insulator does the opposite and instead, stops either from going through. Examples of an insulator is paper, wood, rubber, etc.
Measure how much water has gone in, so you know the concentration.
It depends, for example, it is quite important to know the Kelvin scale (i.e 0 degrees Celsius is 273 K and -273 degrees Celsius is 0 K ) when dealing gases. But I don't know other situations where you would need to know other temperature scales.
Hope this helps and also if you are using Fahrenheit 1 Fahrenheit is -17.22 degrees Celsius
i think the answer is B. They have low reactivity.Hope this helped (:
A because A is the only answer