The study of the elements and forms of matter.
This is a law. That is because it cannot be refuted in any way. A theory often depends on perfect conditions. Even simple theories often are based on perfect conditions that cannot be found on earth. Unlike it, laws are applicable no matter where and how you are. Such are for example Newton's laws or laws of thermodynamics.
Answer:
a. Each set of elements was arranged in special coloumns based on their mass.
Answer:
A. (1/2) N₂(g) + O₂ (g) → NO₂(g)
Explanation:
H°rxn = ∑n*H°f, products - ∑n*H°f, reactants (where n is the number of moles)
H°f is the enthalpy of formation at standard conditions, and it's 0 by the compounds formed by a single element at its atmospheric phase. So, to H°rxn = H°f, products, the number of moles of the product must be 1 and the H°f, reactants must be 0.
Both conditions are only satisfied in letter A.
In letter B, the reactants H and Br are not in the molecule formula, so their H°f is not 0. The mase happens in letter C for O, and in letter E for H. In letter D, 2 moles of the product are being formed.
Mars, because some people believe there used to be life on mars.
Hope this helps.
