| ISOTOPES | Varieties of the same element with differing numbers of neutrons (8) |
| ISOTOPE | One of the variants of an element sharing an atomic number but with differing chemical properties (7) |
| DOUBLESTANDARDS | Duplexes overlooking street and a road constructed by those with differing ideas that unfairly affec |
| CHATEAU | Two varieties of the same hot drink fashionable at castle (7) |
| ALLOTROPY | The existence in the same state of more than one form of the same element with different properties |
| ISOTOPIC | Like different forms of the same element |
| ISOTONES | Atoms that have the same number of neutrons |
| GERANIUM | From Greek for "crane", a plant with seedpods reminiscent of cranes' bills; a pelargonium; or, the pink, red or scarlet colour of many cultivated varieties of the aforesaid flower (8) |
| ISOTONE | Either of two species of atoms with the same number of neutrons and a different number of protons |
| ANTIBODY | Same element turned up in some protein |
| MAGNETAR | A type of neutron star believed to have a very powerful magnetic field |
| TRIGON | Old word for a three-sided polygon, such as an isosceles example; an ancient Greek or Roman lyre or harp; or, a group of three astrological signs belonging to the same element (6) |
| NUCLEUS | Positively charged central core of an atom composed of neutrons and protons |
| NATURE | Scientific journal in which the existence of neutrons was first proposed |
| CABBAGE | Any of various cultivated varieties of the cruciferous plant Brassica oleracea capitata (7) |
| ELDER | Two European varieties of the shrub |
| PULSARS | Types of neutron stars; as slurp (anag.) (7) |
| MEANT | Planned introduction of neutron into core |
| ATOMS | From the ancient Greek meaning "indivisible", units of matter consisting of electrons, protons and neutrons (5) |
| AMERICIUM | Radioactive metallic element synthesized by bombarding uranium or plutonium with neutrons; atomic no. 95 (9) |
