X+2HCl-->XCl₂+H₂
=> X-metal cu valenta II
metalele cu valenta II:
Be(beriliu),Mg(magneziu),Ca(calciu),Sr(strontiu),Ba(bariu),Ra(radiu),Po(poloniu,grupa VI A)
=> Be+2HCl->BeCl₂+H₂
=>Mg+2HCl->MgCl₂+H₂
=>Ca+2HCl->CaCl₂+H₂
=>Sr+2HCl->SrCl₂+H₂
=>Ba+2HCl->BaCl₂+H₂
=>Ra+2HCl->RaCl₂+H₂
=>Po+2HCl->PoCl₂+H₂