<span>There are three atoms of Sn (Stannous or Tin) in</span> 356.13 g of Sn.
<span>One atom of Sn has the atomic mass (m</span>ₐ<span>) of </span>118,71u which means:
356.13/118.71=3 atoms of Sn
The mass number (symbol A) also called atomic mass number or nucleon number is the total number of protons and neutrons in an atomic nucleus. It determines the atomic mass of atoms and it is in the periodic table.
Answer:

Explanation:
Given that,
The distance between the centers of the two oxygen atoms in an oxygen molecule is
.
We need to convert this distance in inches.
We know that,
1 cm = 0.393 inches
We can solve it as follows :

So, the distance between the centers of the two oxygen atoms is
.
The % yield if 500 g of sulfur trioxide reacted with excess water to produce 575 g of sulfuric acid is calculated using the below formula
% yield = actual yield/ theoretical yield x100
actual yield =575 grams
to calculate theoretical yield
find the moles of SO3 used =mass/molar mass
= 500g/ 80 g/mol =6.25 moles
SO3+H2O=H2SO4
by use of mole ratio of SO3 : H2SO4 which is 1:1 the moles of H2SO4 is also= 6.25 moles
the theoretical yield of H2SO4 is therefore = moles /molar mass
= 6.25 x98= 612.5 grams
%yield is therefore= 575 g/612 g x100= 93.9 %
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