Which of the following may have more than one phase?
a. a pure solid
b. a pure liquid
c. a homogeneous mixture
d. a heterogeneous mixture

It wouldn't be D...Go from there All the other could have several changes ...but I don't which would have the most.

Explanation:

Matter is defined as anything that occupies space and has mass, and it is all around us. Solids and liquids are more obviously matter: We can see that they take up space, and their weight tells us that they have mass. Gases are also matter; if gases did not take up space, a balloon would stay collapsed rather than inflate when filled with gas.

Solids, liquids, and gases are the three states of matter commonly found on earth (Figure 1). A solid is rigid and possesses a definite shape. A liquid flows and takes the shape of a container, except that it forms a flat or slightly curved upper surface when acted upon by gravity. (In zero gravity, liquids assume a spherical shape.) Both liquid and solid samples have volumes that are very nearly independent of pressure. A gas takes both the shape and volume of its container.

A beaker labeled solid contains a cube of red matter and says has fixed shape and volume. A beaker labeled liquid contains a brownish-red colored liquid. This beaker says takes shape of container, forms horizontal surfaces, has fixed volume. The beaker labeled gas is filled with a light brown gas. This beaker says expands to fill container.

Figure 1. The three most common states or phases of matter are solid, liquid, and gas.

A fourth state of matter, plasma, occurs naturally in the interiors of stars. A plasma is a gaseous state of matter that contains appreciable numbers of electrically charged particles (Figure 2). The presence of these charged particles imparts unique properties to plasmas that justify their classification as a state of matter distinct from gases. In addition to stars, plasmas are found in some other high-temperature environments (both natural and man-made), such as lightning strikes, certain television screens, and specialized analytical instruments used to detect trace amounts of metals.

The correct answer is d) a heterogeneous mixture

Explanation:

Pure substances (both in liquid and solid state) only have one phase because they are composed of only one element, so you cannot observe differents zones (or "phases").

Mixtures can be classified in homogeneous and heterogeneous. A mixture is homogeneous if there ir only one phase or zone of a determined matter state. For example, a mixture of water and ethanol (they are completely mixed and you cannot observe different zones in the liquid).

A mixture is heterogeneous when you can observe different zones with different states of matter, For example: a mixture of water and oil (they cannot mix completely, you can observe the oil drops in the water). A heterogeneous mixture can be composed by the same substance in different states, for example: water with ice (you can see a block of ice in the water!).

So, the only in which you have more than one phase is in a heterogeneous mixture.

colorless gas, exhibiting a blue glow when placed in an electric field

b) solid

its a type of rock