NEET · Chemistry · Hydrogen — Forms & Isotopes

Exercise and reference answers

Matching pairs

1. A

   Protium (¹H)

   B

   1 proton, 0 neutrons (most abundant)

2. A

   Deuterium (²H)

   B

   1 proton, 1 neutron

3. A

   Tritium (³H)

   B

   1 proton, 2 neutrons (radioactive)

4. A

   Ortho-hydrogen

   B

   Both nuclear spins parallel

5. A

   Para-hydrogen

   B

   Nuclear spins antiparallel

6. A

   Heavy water (D₂O)

   B

   Used as a neutron moderator

Instructions

Match each hydrogen variant to its definition.