4. Which of the following sets of substances contains only mixtures? *
gold, carbon, and air
brass, water, and air
orange juice, ocean water, and air
O blood, sodium chloride (NaCl), and air
orange juice, ocean water, and air all all mixtures.
gold in the first answer is a pure substance and so is water in the second. this eliminates those two answers. sodium chloride in the fourth answer is also a pure substance. pure substances have a uniform and definite composition.