Answer:
The correct answer is a scientific law.
Explanation:
The laws of science or scientific laws refer to the statements, which predict or illustrate an array of natural processes. It is a statement based on observations or spontaneous experiments, which illustrate some characteristics of the natural world.
The term law exhibits different uses in various circumstances, that is, across all the branches of natural science. The laws are formulated through data and can be further created via mathematics, in all the conditions, they are indirectly or directly based on empirical evidence. The scientific laws recapitulate the outcomes of observations or experiments, generally within some point of application.
It was created about 6,000 years ago
Answer: Balanced molecular equation :

Total ionic equation:
The net ionic equation:

Explanation:
Complete ionic equation : In complete ionic equation, all the substances that are strong electrolyte are present in an aqueous state as ions.
Net ionic equation : In the net ionic equations, we are not include the spectator ions in the equations.
Spectator ions : The ions present on reactant and product side which do not participate in a reactions. The same ions present on both the sides.
When sodium phosphate and zinc acetate then it gives zinc phosphate and sodium acetate as product.
The balanced molecular equation will be,

The total ionic equation in separated aqueous solution will be,

In this equation, and are the spectator ions.
By removing the spectator ions from the balanced ionic equation, we get the net ionic equation.
The net ionic equation will be,

First of all the ethylamine is base so will be react with water to take the proton from the water (H⁺) , because water is amphoteric will react with bases as acid and acids as a base, so the water in this case will react as an acid and will gives the proton to the base.
In the picture you may see the chemical equation and the structure of the products.