f (BeO) = 1/5f (MnSO4) = 1/6f (Na3PO4) = 1/8f (HNO2) = 1/7f (H2S) = 1/10f (Mn(OH)2) = 1/6f (AgOH) = 1/8
f (BeO) = 1/5
f (MnSO4) = 1/6
f (Na3PO4) = 1/8
f (HNO2) = 1/7
f (H2S) = 1/10
f (Mn(OH)2) = 1/6
f (AgOH) = 1/8