Select any notation of the following elements where there is an odd number of neutrons

The number of neutrons is the mass number (top number) minus the atomic number (bottom number). We need to find isotopes with an odd number of neutrons. For 3/1 H, neutrons = 3-1=2 (even). For 9/4 Be, neutrons = 9-4=5 (odd). For 6/3 Li, neutrons = 6-3=3 (odd). For 1/1 H, neutrons = 1-1=0 (even). For 11/5 B, neutrons = 11-5=6 (even). For 12/6 C, neutrons = 12-6=6 (even). Therefore, the elements with an odd number of neutrons are 9/4 Be and 6/3 Li.