Question

The correct number of atoms of each element present in the formula (NH4)2S is

Answer 1

The number of atoms corresponding to the molecule is in the lower part of the atoms, when there is no number it will mean that the atom is present only once.

So, we have that in one molecule of NH4 there will be:

`\begin{gathered} N\rightarrow1\text{ atom of nitrogen} \\ H_4\rightarrow4\text{ atoms of hydrogen} \end{gathered}`

Outside the parentheses we see that there is a number two (NH4)2, this means that there are two molecules of NH4.

So we have:

`\begin{gathered} (NH_4)2\rightarrow(N*2)\rightarrow1*2=2\text{ atoms of nitrogen} \\ \text{ }\rightarrow(H_4*2)\rightarrow4*2=8\text{ atoms of hydrogen} \end{gathered}`

And we have outside the molecule an atom of S

`S\rightarrow1\text{ atom of S}`

So, we have in total:

`2-N,8-H,1-S_{}`

The answer will be the last one, 2-N, 8-H, 1-S