The correct option is C Chalk water
Mixture is a combination of two or more different substances. The constituents of mixture can be separated by simple physical means.
- Chalk water is a mixture in which chalk is suspended in water.
- Air is a mixture of different gases like nitrogen, oxygen, argon, helium, etc.
- Salt water is a mixture in which salt is dissolved in water.
Iron is not an example of a mixture since it is made up of only one type of particles, i.e. atoms of iron.