Reductic acid contains 52-687. Carbon, s. 30%. hydrogen, and 42.071. oxygen. Its simplest formula is the same as its molecular formula. The number of hydrog en atoms in a molecule of reductic acid is ​

r just means there's a number of carbon in teh chain. for example rcooh means that after x number of carbon, the chain ends with cooh.

explanation:

answer : a model is often used to explain and make things easier to understand when any scientific topic needs to be demonstrated and explained.

as in this case where a scientist wants to use a model to present the results of his detailed scientific investigation. he should do it as it will him to make the audience understand the concept in a much better way. also, it can be changed according to new scientific understandings.

c, liquids evaporate, creating a gas

catya that's not even a b or c