Question

Which of the following best demonstratesthat a chemical change has taken place?

The mass of the salt solution, beaker and nails
decreased.
The volume of the salt solution has decreased.
The salt solution was discolored after a week.
The iron nail is still undissolved in the solution
after a week.

Answer 1

the last one

Step-by-step explanation:

THE IRON NAIL IS STILL UNDISSOLVED IN SOLUTION AFTER A WEEK