A chemist wants to synthesize ammonia, which has the chemical formula NH₃. Which of the following reactant lists is the only one that could possibly be used to produce ammonia?

Methane (CH₄) and water (H₂O)

Nitrogen gas (N₂) and hydrogen gas (H₂)

Carbon dioxide (CO₂) and hydrogen gas (H₂)

Sodium chloride (NaCl) and water (H₂O)

A student incorrectly claims that they can produce carbon dioxide (CO₂) by reacting pure hydrogen gas (H₂) with pure oxygen gas (O₂). Why is this impossible?

The reaction would produce water (H₂O) instead, as no carbon atoms are available in the reactants.

The reaction requires a metal catalyst, which was not mentioned as being present in the experiment.

Hydrogen and oxygen are both non-metals and therefore cannot react with each other to form a new compound.

Carbon dioxide is a stable molecule and can only be formed by breaking down more complex organic matter.

The Law of Conservation of Energy

The Law of Universal Gravitation

The Law of Conservation of Matter

The Law of Definite Proportions

The number of molecules on the reactant side must equal the number of molecules on the product side.

The number of atoms of each element on the reactant side must equal the number of atoms of that same element on the product side.

The physical state (solid, liquid, gas) of the reactants must be the same as the physical state of the products.

The total electrical charge of the reactants must always be zero.