Answer:
Law of definite proportions, statement that every chemical compound contains fixed and constant proportions (by mass) of its constituent elements.
I did the test and the answer is C.
Dimitri Mendeleev was the first to put elements together on a table. He knew there were elements missing but he noticed a trend in some of the elements known at the time. Sodium, Lithium and other alkali metals all have the same properties so he put them under the same column and created other columns with similar attributes (Halogens, Noble gases, Alkaline earth metals). Over the years, new elements were discovered and put into the rough outline that Mendeleev created.
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Answer:
See the attached file for the structure.
Explanation:
Find attached for the explanation