We found 10 dictionaries that define the word atomic numbers:

General (7 matching dictionaries)

1. atomic numbers: Merriam-Webster
2. atomic numbers: Collins English Dictionary
3. atomic numbers: Vocabulary.com
4. atomic numbers: Cambridge Advanced Learner's Dictionary
5. atomic numbers: Wiktionary
6. Atomic numbers: Wikipedia, the Free Encyclopedia
7. Atomic numbers: TheFreeDictionary.com

Computing (1 matching dictionary)

8. Atomic numbers: Encyclopedia

Medicine (2 matching dictionaries)

9. atomic numbers: Merriam-Webster Medical Dictionary
10. Atomic numbers: Medical dictionary

(Note: See atomic_number as well.)

Definitions from Wiktionary (atomic number) ▸ noun:  (physics, chemistry) The number of protons in an atom. Symbol: Z ▸ Also see atomic_number ▸ Words similar to atomic numbers ▸ Usage examples for atomic numbers ▸ Idioms related to atomic numbers ▸ Wikipedia articles (New!) ▸ Words that often appear near atomic numbers ▸ Rhymes of atomic numbers ▸ Invented words related to atomic numbers