Final answer:
Bringing 30 lit birthday candles close to a balloon on your birthday would likely cause the balloon to burst due to the heat, resulting in a loud bang.
Step-by-step explanation:
When you light 30 candles on your birthday cake and bring them close to a balloon, the expected result would be that the heat from the candles' flames will cause the balloon to burst, creating a loud bang. This happens because the balloon's surface cannot withstand the heat of the flame, and the pressure inside the balloon rapidly escapes once the surface is compromised. On the occasion of a birthday, candles are traditionally blown out, but in this case, lighting them close to a balloon creates a reaction that serves as an example of how heat affects different materials.