Dictionary.info
BROWSE DICTIONARY
BROWSE DICTIONARY
IELTS Words
TOEFL Words
GRE Words
SAT Words
GMAT Words
English Learning
Learning
IELTS Lessons
Exam English ✓
Graduate tests
Test English Info
Oxford Collocation Dictionary
Wordnet Online
IELTS Lessons
Google Dictionary
DEFINITIONS
SYNONYMS
Search
top definitions
M-shell
[
em
-shel ]
SHOW IPA
/ ˈɛmˌʃɛl /
PHONETIC RESPELLING
noun
Physics
.
the third shell of electrons surrounding the nucleus of an atom and containing, when filled, 18 electrons having principal quantum number three.
Compare
K-shell
,
L-shell
,
N-shell
.
Origin of M-shell
First recorded in 1920–25