Explanation :
As we know that Mendeleev arranged the elements in horizontal rows and vertical columns of a table in order of their increasing relative atomic weights.
He placed the elements with similar nature in the same group.
According to the question, the atomic weight of iodine is less than the atomic weight of tellurium. So according to this, iodine should be placed before tellurium in Mendeleev's tables. But Mendeleev placed iodine after tellurium in his original periodic table.
However, iodine has similar chemical properties to chlorine and bromine. So, in order to make iodine queue up with chlorine and bromine in his periodic table, Mendeleev exchanged the positions of iodine and tellurium.
As we know that the positions of iodine and tellurium were reversed in Mendeleev's table because iodine has one naturally occurring isotope that is iodine-127 and tellurium isotopes are tellurium-128 and tellurium-130.
Due to high relative abundance of tellurium isotopes gives tellurium the greater relative atomic mass.
Answer:
13. Index Fossils
14. Index Fossils
15. C
16. Geologists use index fossils to define geological periods.
17. C
18. A
Insects and dogs are both in the Animalia classification.
The answer to you’re question is C. NH3
Answer:
Ther answerr is A only solid A.
Explanation:
The density of water is 1 g/cm3 so anything above that will sink, but as you can see solid A dosnt ev en reach one./ so It will float on water. the other two are over 1 g/cm3.
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