Because they insulate either the heat or the coolness within the food item. But keep in mind- when it comes to electricity aluminum isn’t an insulator.
Answer: 63.26%
Explanation:
If we let the abundance of the first isotope be x, then:

Which is equal to <u>63.26%</u>
One way you can work out the rate of reaction is by the amount of product that is produced to time. This can also be done with heat and time.
Hope this helps! :)