\(n_A=\dfrac{5,6}{22,4}=0,25\left(mol\right)=>M_A=\dfrac{7}{0,25}=28\left(g/mol\right)\)
=> A là N2
\(n_A=\dfrac{5.6}{22.4}=0.25\left(mol\right)\)
\(m_A=\dfrac{7}{0.25}=28\)
=>A là Silic
\(n_A=\dfrac{V}{22,4}=\dfrac{5,6}{22,4}=0,25\left(mol\right)\)
\(M_A=\dfrac{m}{n}=\dfrac{7}{0,25}=28\left(\dfrac{g}{mol}\right)\)
\(\Rightarrow A.là.N_2\)