Question

1. a bicycle left outside develops rust after several weeks.

type of change:
explanation:

Explanation:

The bicycle's metal parts (like the frame) react with oxygen and moisture in the air to form rust (iron oxide). A chemical change involves the formation of new substances, and rust is a new substance different from the original metal. So this is a chemical change.

The bicycle's metal (e.g., iron) reacts with oxygen and water to form rust (a new substance, iron oxide), indicating a chemical change as new substances are created.

Answer:

Type of change: Chemical change