To save this word, you'll need to log in.
Definition of molecular beam
: a stream of molecules that escape at thermal speeds from a heated enclosure, that are controlled by slits so as to move in nearly parallel paths, and that are used in determining the electric and magnetic properties of atoms, atomic nuclei, and molecules
Comments on molecular beam
What made you want to look up molecular beam? Please tell us where you read or heard it (including the quote, if possible).
Test Your Vocabulary
Words for Summer: A Quiz
- Which of the following words means “of or relating to summer”?
Can you spell these 10 commonly misspelled words?
TAKE THE QUIZ
Test Your Knowledge - and learn some interesting things along the way.
TAKE THE QUIZLove words? Need even more definitions?
Merriam-Webster unabridgedWords at Play
Ask the Editors
Word Games
- Words for Summer: A Quiz
Test your knowledge of words related to the season of longer days and vacations.
Take the quiz - A More Exception(al) Quiz
Which of these things doesn't belong?
Take the quiz - Spell It
Can you spell these 10 commonly misspelled words?
Take the quiz - Bee Cubed
Listen to the words and spell through all three levels.
Play the game
Share molecular beam