Out of two salts baking soda and washing soda, which salt does not contain water of crystallisation?

Name the phenomenon in which non-biodegradable chemical gets accumulated at each trophic level of a food chain.

Upto which element the law of octaves was found to be applicable?

Name the reaction which is responsible for the large energy production in the sun?

Name the sensory receptors founds in the nose and on the tongue.