Why does solid water float?
An ice cube stays near the surface of your drink. Being solid is not what decides whether something sinks.
The hidden mechanism
Why is the sky blue if sunlight looks white?
The colour above you is a clue to a journey. Sunlight changes direction when it meets the atmosphere.
Can adding sound make things quieter?
Two disturbances can reinforce each other. With the right timing, they can also partly cancel. Follow what happens where they meet.