Which is a property of every heterogeneous mixture?

The mixture is made up of at least two different states.
The mixture is made up of something dissolved in a liquid.
The composition of the mixture is the same throughout.
The characteristics of the mixture change within a sample.

Aglow stick contains a glass vial with chemicals. when the glow stick is bent, the vial breaks and the chemicals react to produce a glow. a science student observes that a glow stick kept in the freezer glows for a longer duration than a glow stick kept at room temperature. what conclusion can be drawn based on the observation? be sure to note the outcome and test variables in the conclusion.