What law is known as the law of action-reaction

What does the symbol (–hfus) indicate in a phase change?

The picture represents the process that produces most of the energy used by living organisms on earth. which process is represented in the picture? a) the magnetic attraction between two hydrogen nuclei. b) the fusion of hydrogen nuclei to produce a helium nucleus in the core of the sun. c) the fission of hydrogen nuclei to produce a helium nucleus in the core of the sun. d) the chemical reaction between hydrogen nuclei to produce a helium nucleus in earth's atmosphere.

There are approximately 15 milliliters (ml) in 1 tablespoon (tbsp). what expression can be used to find the approximate number of milliliters in 3 tbsp?