Answer:
O a polymer
Explanation:
When many repeating simple subunits are joined together, this results into a polymer.
The simplest unit or smallest unit of any substance is called a monomer. When many units of a monomer joins together, a polymer results.
- For proteins, the monomeric unit is amino-acid.
- When they combine they form longer chain molecules called proteins.
- For carbohydrates, the monomeric unit is called glucose.
- When they are combined they give us a wide range of carbohydrate molecules.
Answer:
Endocrine disruptor
Explanation:
This means that the four substances, even they are used in different areas like gardening, plastics or pots, all of them change the endocrine system in humans because they imitate the natural hormones and the body stops to produce them or starts to produce more hormones than the body needs.
They are correlate with some illness like cancer, thyroid problems and infertility.
- See charge on ion is -1 .
Hence it has taken 1 electron
Now first look at EC of Fluorine(F)

- Now one electron added .hence no of electrons is 10now
Look at the EC

Or
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Option C is correct.
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.