Element 1 is polished to form a smooth surface. Element 2 is heated and evaporates. Element 3 develops a white, powdery surface after standing in air. Element 4 is separated from a mixture by filtration.
I am hesitating between 4 options to answer the following question, which option should I choose?
Question: Which is a chemical change?
Possibilities:
- Element 1 is polished to form a smooth surface.
- Element 2 is heated and evaporates.
- Element 3 develops a white, powdery surface after standing in air.
- Element 4 is separated from a mixture by filtration.

Element 3 develops a white, powdery surface after standing in air.