A colored line, as long as it is one single piece, not broken
Answer:
It is a chemical change.
Explanation:
When the electricity is off, the filament cools down to its original physical state. This physical process repeats every time the light is turned on and off. However, if the bulb is cracked and air is introduced, the oxygen in the air reacts with the tungsten filament which then undergoes a chemical change.
Answer: When the air particles inside the balloon become colder, they slow down and do not hit the inside of the balloon as often, so the balloon's volume decreases.
