Choose the correct answer:
1. When a metal reacts with nitric acid, no hydrogen gas is produced. However, the metal that produces hydrogen gas when it reacts with very dilute nitric acid is
2. When metals react with \(HCl\), hydrogen gas is produced; when they react with \(HNO_3\), no hydrogen gas is produced. On the other hand, magnesium and manganese form hydrogen gas when they react with very dilute \(HNO_3\). The metal that is unaffected by \(HNO_3\) and \(HCl\) is