30% should be the percentage of oxygen if the total mass of fe2o3 is 160.
If Robert has 4 grams of a substance and Jill has 10 grams of the same substance <span>Jill's sample will weigh more than Robert's sample.</span>
The mass of magnesium in 
atoms is 240 g.
Answer: Option A
<u>Explanation:</u>
First, we have to convert the atoms to moles of magnesium.
We know that atoms are present in 1 mole of magnesium. So,
Thus,
Thus, 240 g of Magnesium is present in atoms.
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:
doublet
Explanation:
Proton MNR is used for the determination of no. of equivalents protons in a molecule
In the molecule, single NMR signal is produced for each set of protons.
Signal splitting is called spin-spin coupling and the splitting of signals depends upon the no. of neighboring proton.
The no. of signal for a proton is equal to n+1, where n is neighboring protons.
In 1-bromo-2-methylpropane, neighboring proton for both methyl protons are one. But the chemical environment of both the methyl protons are different.
Neighboring proton for methyl protons = 1
No. of signal for methyl protons = 1+1 =2
Hence, two doublets will be generated for each set of methyl protons. protons.
