Question

Calcule o número de átomos contidos em 8 g de O2.

Answer 1

O2⇒ 2.16g = 32g

6x10²³ moléculas ----- 32g
x -------------------------- 8 g
32x= 8.6.10²³
x= 1,5.10²³ moléculas

Answer 2

$\large\boxed{\begin{array}{l}\rm 12\cdot 10^{23}\acute atomos\longrightarrow 32~g\\\rm x\longrightarrow 8~g\\\rm 32 x=96\cdot10^{23}\\\\\rm x=\dfrac{96\cdot10^{23}}{32}\\\\\rm x=3\cdot 10^{23}~\acute atomos\end{array}}$