How is a scientific law different from a scientific theory?
1.
a theory is why something happens and a law is how something happens.
2.
a theory is used for biology and chemistry and a law is used for physics.
3.
a theory becomes a law after a long period of time has passed.
4.
a theory cannot be disproved but a law can be disproved.

1. A theory is why something happens and a law is how something happens.

Explanation:

Whenever scientists or people studying scientific disciplines face any  scientific question, they try to solve it through proper scientific method. Two of the most important steps of scientific methods are to propose a theory as an answer of the question and after it formulate a law if it can be formed.

In simple terms we can think of a theory as an logical answer that why a certain phenomenon occurs. On the other hand a law is a statement that shows how a phenomenon occurs and it can help in predicting about the phenomenon. Laws are relatively general as compared to theory because theory is logical and well reasoned explanation about a certain happening.

A theory grows into a law when several group of people work on the same question and find same answer in such a way that it is universally approved. Theories can be revised after repeating experiment or condition however scientific law can never be proved wrong and it remains same.

For example: Darwin's theory called Neo- Darwinism in which he said that living organisms can be produced from non-living organism was disapproved by scientists after careful experimentation. It explained the  reasoning that why living organisms can be produced from non-living organisms however if it had been proved by all scientists it would become a law which just explains that how living organisms are produced from non living in a general one or two lines statement. For example: Newton's law of motion.

Hope it helps!

i believe it would be the lungs.