Which of the following statements are true? (matrices and determenents)

1. If any row of a square matrix is zero, its determinant is zero.

2. If all numbers in a matrix are equal, its determinant is zero.

3. The determinant of any identity matrix is zero.

4. The determinant of a matrix with all positive numbers is always positive.

5. The determinant of any zero matrix is zero.

(multiple choice)