pls answer properly

1. This is the physical appearance of a substance. What is it?
D. Non-uniform
A. Complicated
B. Homogeneous
C. Heterogeneous

2. All pure substances have
A. the same color.
B. the same composition.
C.the same physical state.
D. a definite set of properties
.
3. Which of the following is NOT a pure substance?
A iron
B. sugar
C. salt
D. rain water

4. Which of the following statement is INCORRECT about compound?
A. A compound is combined chemically in fixed proportion
B. A compound is combined chemically in variable proportion
C. All compounds are molecules, but not all molecules are compounds
D. A compound is a pure substance composed of two or more elements

5. A compound is a pure chemical substance made of two or more different chemical
A. element
B. particle
C. material
D. composition​