useless trivia: What Word Means: Surely?

Questions

Approximately how many times sweeter is saccharin than sucrose?

What is the chemical name for water?

Tomography is a scanning technique which uses X-rays for photographing particular slices of the what?

What is the term for a fine mist or fog which is dispersed in and carried by a gas?

Who was said to have used a monocle made of emerald to improve his vision at the arena?