\(V_{kk}=33,6l\Rightarrow V_{O_2}=6,72l\Rightarrow n_{O_2}=0,3mol\Rightarrow m_{O_2}=9,6g\)
BTKL: \(m_M=m_{sp}-m_{O_2}=20,4-9,6=10,8g\)
\(4M+3O_2\underrightarrow{t^o}2M_2O_3\)
\(\dfrac{10,8}{M}\) 0,3
\(\Rightarrow\dfrac{10,8}{M}\cdot3=0,3\cdot4\Rightarrow M=27\Rightarrow Al\)