General terms related to thermodynamics

Define the term thermodynamics.

General term of an AP

Select the option that is related to the third term in the same way as the second term is related to the first term and the sixth term is related to the fifth term. 21 : 112 : 36 : ? :: 51 : 262

Select the option that is related to the third term in the same way as the second term is related to the first term. Tomato : Red :: Leaf:?