Question: which elements are nmr active?
Answer: 2.1. Hydrogen (1H, 2H, 3H) ... 
2.1. Applications of protium (1H) ... 
2.1. Applications of deuterium (2H) ... 
2.1. Applications of tritium (3H) ... 
2.2. Helium (3He) ... 
2.3. Lithium (7Li) ... 
2.4. Boron (10B, 11B) ... 
2.5. Carbon (13C)