Which one of the following is not a mixture?
A
Air
B
Mercury
C
Milk
D
Cement
Verified Correct Answer: B.
Step-by-Step Mathematical Solution
A mixture is a material made up of two or more different chemical substances which are not chemically combined.
Mercury is a chemical element with the symbol Hg and atomic number 80.
Source: WAEC / JAMB / NECO Classroom Archive (Record #60424)