The diagram below shows what happens to the molecules of two substances, A and B, when they are mixed together. Explain what the diagram models about physical and chemical changes at the molecular scale.
Substance A white
Substance B black
The diagram models a physical change at the molecular scale. The molecules of substances A and B are shown as separate white and black clusters before they are mixed together. After they are mixed, the molecules are interspersed and form a mixture of white and black molecules.
This mixing process does not involve any chemical reactions occurring between the molecules of substances A and B. Instead, it represents a physical change where the molecules are simply mixed together and distributed evenly throughout the mixture. This demonstrates how substances can be physically combined without changing their chemical identity.
In summary, the diagram models a physical change at the molecular scale, specifically the mixing of two substances to form a homogeneous mixture.