Question

Which of the following has a maximum number of atoms?
A)$24\,g\,C\left( {12} \right)$
B)$56\,g\,Fe\left( {56} \right)$
C)$27\,g\,Al\left( {27} \right)$
D)$108\,g\,Ag\left( {108} \right)$

Answer 1

Hint: We know that Avogadro’s number is the number of atoms in one mole of any substance. The units of Avogadro’s number are electrons, atoms, ions, or molecules depending on the nature of the substance.
${\text{1}}\,{\text{mole = 6}}{\text{.022 \times 1}}{{\text{0}}^{{\text{23}}}}\,{\text{unit}}$

Complete step by step answer:
We know that Avogadro’s number is the number of atoms in one mole of any substance. The units of Avogadro’s number are electrons, atoms, ions, or molecules depending on the nature of the substance.
${\text{1}}\,{\text{mole = 6}}{\text{.022 \times 1}}{{\text{0}}^{{\text{23}}}}\,{\text{unit}}$
Complete step by step answer:
We know that,
The atomic mass of the substance is the sum of protons or electrons in an atom. For example, the atomic mass of carbon is 6 which means the number of electrons is six.
The number of atoms in carbon can be calculated as,
The molar mass of carbon is $12\,g/mol.$
The mass of carbon is $24\,g.$
The Avogadro’s number is $6.022 \times {10^{23}}\,atoms.$
Now we can be calculate the number of atoms in $24\,g$ of carbon as,
$24\,g \times \left( {\dfrac{{6.022 \times {{10}^{23}}\,atoms}}{{12\,g}}} \right) = 12.04 \times {10^{23}}\,atoms$
The number of atoms in $24\,g$ of carbon is $12.04 \times {10^{23}}{\text{ }}atoms.$
Let us calculate the number of atoms in iron.
The molar mass of Iron is $56\,g/mol.$
The mass of Iron is $56\,g.$
The Avogadro’s number is $6.022 \times {10^{23}}\,atoms.$
The number of atoms in $56\,g$ of Iron can be calculated as,
$56\,g \times \left( {\dfrac{{6.022 \times {{10}^{23}}\,atoms}}{{56\,g}}} \right) = 6.022 \times {10^{23}}\,atoms$
The number of atoms in $56\,g$ of Iron is $6.022 \times {10^{23}}\,atoms$
Let us calculate the number of atoms in Aluminium.
The molar mass of Aluminium is $27\,g/mol.$
The mass of Aluminium is $27\,g.$
The Avogadro’s number is $6.022 \times {10^{23}}\,atoms.$
The number of atoms in $27\,g$ of Aluminium can be calculated as,
$27\,g\, \times \left( {\dfrac{{6.022 \times {{10}^{23}}\,atoms}}{{27\,g}}} \right) = 6.022 \times {10^{23}}\,atoms$
The number of atoms in $27\,g$ of Aluminium is $6.022 \times {10^{23}}\,atoms$
Let us calculate the number of atoms in Silver.
The molar mass of Silver is $108\,g/mol.$
The mass of Silver is $108\,g.$
The Avogadro’s number is $6.022 \times {10^{23}}\,atoms.$
The number of atoms in $108\,g$ of Silver can be calculated as,
$108\,g\, \times \left( {\dfrac{{6.022 \times {{10}^{23}}\,atoms}}{{108\,g}}} \right) = 6.022 \times {10^{23}}\,atoms$
The number of atoms in $108\,g$ of Silver is $6.022 \times {10^{23}}\,atoms$
Thus, carbon has a maximum number of atoms.

So, the correct answer is Option A .

Note:
We can find the elements with the maximum number of atoms can also be found by calculating the number of moles. We know that, number of moles of an element and the number of atoms are directly proportional.
The number of moles can be calculated using the formula,
$Moles = \dfrac{{Mass}}{{Molecular\,Mass}}$