Which of the following is NOT a true statement about ionic crystals?
1.) Omitted because I understand why this is false.
2.) Omitted because I understand why this is false.
3.) Omitted because I understand why this is false.
4.) Solid ionic compounds cannot conduct electricity, since the ions are held in place by ionic bonds.
5.) All of the above statements are true.

This is on a practice exam and the professor has 5 marked as the correct answer, but I think 4 is the correct answer. Why is 4 incorrect?

Question

Which of the following is NOT a true statement about  ionic crystals?
1.) Omitted because I understand why this is false.
2.) Omitted because I understand why this is false.
3.) Omitted because I understand why this is false.
4.) Solid ionic compounds cannot conduct electricity, since the ions are held in place by ionic bonds.
5.) All of the above statements are true.

This is on a practice exam and the professor has 5 marked as the correct answer, but I think 4 is the correct answer. Why is 4 incorrect?