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:
1.1 liters
1.2 liters
1.5 liters
Explanation:
Precision in data refers to how close the experimental values of an experiment are to one another irrespective of the true or accepted value. In other words, a set of values are said to be PRECISE if they are close to one another.
In this case, data was collected after conducting an experiment about the amount, in liters, of water a specific plant needs per month. However, according to the set of experimental values provided, only 1.1 litres, 1.2litres and 1.5litres are close to one another and, hence, are said to be PRECISE even if they are not close to the accepted value of 6litres.
Answer:
Noble Gases are very stable because...
1) Noble Gases have a full octet
2) Low chemical reactivity
Explanation:
This means that is has 8 valence electrons so it won't need any more, so it is less likely to react with other substances.
The answer is D. Effective collisions lead to chemical reactions!