Question

a piece of iron chain is left in water for a few days and changes color from gray to reddish brown. this color change is most likely an example of–
melting.
bending.
burning.
rusting.
question 3

Explanation:

• Melting is the process of a solid turning into a liquid due to heat, which is not what's happening here as the iron chain is in water and changing color, not state.
• Bending is a physical change involving the shape of the object, not a color change, so this is incorrect.
• Burning involves combustion with heat and flame, and the iron chain is just left in water, not being burned.
• Rusting is the chemical reaction of iron with oxygen and water to form iron oxide (rust), which is reddish - brown. When an iron chain is left in water, the conditions for rusting (presence of iron, water, and oxygen from the air dissolved in water) are met, and the color change to reddish - brown is characteristic of rust formation.

Answer:

D. rusting.