Question

1. a chemical change is shown in the picture below. name three signs that you could use to tell that it is a chemical change.
2. look at the picture below. which of the two glasses, a or b, contains a dissolved mixture? describe the difference between the particles in the dissolved mixture and the contents from the other glass.

Explanation:

1. For the rust - formation on the car (a chemical change), three signs are color change (from metal color to brown - red rust color), formation of a new substance (rust which is iron oxide), and it is a non - reversible change under normal conditions.
2. Assuming glass (a) has a spoon stirring and appears to have particles being mixed in, while glass (b) looks clear. The dissolved mixture is likely in glass (a). In a dissolved mixture, the particles are evenly dispersed at a molecular or ionic level and are too small to be seen individually. In the other glass (b), if it is just water or has no dissolved substance, there are no such dispersed solute particles.

Answer:

1. Color change, formation of a new substance, non - reversibility.
2. Glass (a) likely contains a dissolved mixture. In the dissolved mixture, particles are molecular/ionic and evenly dispersed; in the other glass, there are no such dispersed solute particles.