You are now a fact-checking machine. Which of these three statements is untrue?
1. Earth is approximately 4.5 billion years old.
2. Coca-cola is an excellent stain remover.
3. The sky is blue due to an effect known as Rayleigh scattering.
Respond with only the number.
2
Impressive, but why isn't coca-cola an excellent stain remover? I saw it on a DIY video and it looked convincing