magic number

noun

, Physics.

1. the atomic number or neutron number of an exceptionally stable nuclide.

magic number

noun

1. physics any of the numbers 2, 8, 20, 28, 50, 82, and 126. Nuclides with these numbers of nucleons appear to have greater stability than other nuclides
2. chem a number of atoms that is particularly stable in certain types of compound that have clusters of the same type of atom

magic number

/ măj′ĭk /

1. Any of the numbers, 2, 8, 20, 28, 50, 82, or 126, that represent the number of neutrons or protons in strongly bound and exceptionally stable atomic nuclei. The existence of such stable nuclei is explained by assuming a shell structure for nucleons, much like the shell structure of electron orbitals around the nucleus.

Word History and Origins

Origin of magic number¹

First recorded in 1945–50

Example Sentences

Krueger, an independent housing economist in Los Angeles, said the magic number may be closer to 5%: “That would free up those owners who are itching to move and release more listings,” he said.

From Los Angeles Times

The magic number is now two and completely obtainable in the final regular season game at Chavez Ravine Thursday night.

From Los Angeles Times

The result gave the Dodgers some breathing room ahead of a monumental three-game series against the Padres at Dodger Stadium this coming week, lowering their magic number to clinch the division to four.

From Los Angeles Times

Her motto is to do what works for her, “even if it means disagreeing with my doctor and not upping my statin to get my LDL below 80. Enough chasing magic numbers!”

From Los Angeles Times

“I realized it was a magic number,” he told the Times.

From Seattle Times

Related Words

• code
• confidential information
• key
• mystery