Answer:
- <em>He realized that some elements had not been discovered.</em>
Explanation:
Some scientists that tried to arrange the list of elements known before Mendeleev include Antoine Lavoisier, Johann Döbereiner, Alexandre Béguyer de Chancourtois, John Newlands, and Julius Lothar Meyer.
<em>Dimitri Mendeleev</em> was so succesful that he is recognized as the most important in such work.
Mendeleev by writing the properties of the elements on cards elaborated by him, and "playing" trying to order them, realized that, some properties regularly (periodically) repeated.
The elements were sorted in increasing atomic weight (which is not the actual order in the periodic table), but when an element did not meet the pattern discovered, he moved it to a position were its properties fitted.
The amazing creativity of Mendeleev led him to leave blanks for what he thought were places that should be occupied by elements yet undiscovered. More amazing is that he was able to predict the properties of some of those elements.
When years after some of the elements were discovered, the genius of Mendeleev was proven because the "new" elements had the properties predicted by him.
Answer:
c. 77 %
Explanation:
Percent mass (% mass) of solute = mass of solute/mass of solution × 100
According to this question, a mountain dew solution weighing 300grams contains 231 g of sugar. This means that:
% mass of sugar = 231g/300g × 100
% mass of sugar = 0.77 × 100
% mass of sugar = 77%.
Answer:
B
Explanation:
catches fire easily, there is a chemical in the substance that reacts to the flame, and a key to it being a chemical property is when exposed to other substances, there is a chemical in the other substances that makes it chemically react
Freeze-Thaw Weathering
This action can widen the cracks in the rock, and when the temperature rises above freezing, the ice thaws, allowing the water to seep further into the cracks. As this process of freezing and thawing happens repeatedly, the rock begins to weaken and eventually breaks apart into angular fragments.
