The average mass of an atom is calculated with the formula:
average mass = abundance of isotope (1) × mass of isotope (1) + abundance of isotope (2) × mass of isotope (2) + ... an so on
For the boron we have two isotopes, so the formula will become:
average mass of boron = abundance of isotope (1) × mass of isotope (1) + abundance of isotope (2) × mass of isotope (2)
We plug in the values:
10.81 = 0.1980 × 10.012938 + 0.8020 × mass of isotope (2)
10.81 = 1.98 + 0.8020 × mass of isotope (2)
10.81 - 1.98 = 0.8020 × mass of isotope (2)
8.83 = 0.8020 × mass of isotope (2)
mass of isotope (2) = 8.83 / 0.8020
mass of isotope (2) = 11.009975
mass of isotope (1) = 10.012938 (given by the question)
Formula for diarsenic pentoxide
As2O5
See if the carbon atoms are SP2 or Sp they the coplanirty is more and if its Sp3 hybridization it cant be in coplanar as Sp3 is having Td shape where as sp2 and sp are not :)
Answer:
(See explanation for further details)
Explanation:
1) The quantity of moles of sulfur is:


2) The number of atoms of helium is:


3) The quantity of moles of carbon monoxide is:


4) The number of molecules of sulfur dioxide is:


5) The quantity of moles of sodium chloride is:


6) The number of formula units of magnesium iodide is:


7) The quantity of moles of potassium permanganate is:


8) The number of molecules of carbon tetrachloride is:


9) The quantity of moles of aluminium is:


10) The number of molecules of oxygen difluoride is:


1) Magnesium Chloride
2) Sodium Bromide
3) Magnesium Oxide
4) Nickel (III) Fluoride
5) Aluminum Chloride
6) <span>Rubidium Sulfide
7) Gallium Nitride
8) Calcium Sulfide
9) </span><span>Lead (IV) Oxide
10) </span><span>Cobalt (II) Oxide
</span>11) B<span>eryllium Sulfide
12) </span><span>Cesium Nitride</span>