Syllables    Rhymes    Quiz

radioactive

How many syllables in radioactive?

  5 syllables

Divide radioactive into syllables:   ra-di-o-ac-tive
Primary syllable stress:   ra-di-o-ac-tive
Secondary syllable stress:   ra-di-o-ac-tive
How to pronounce radioactive:   rey-dee-oh-ak-tiv
How to say radioactive:

Cite This Source

Bibliography Citations
MLA   |    APA   |   Chicago Manual Style
"radioactive." HowManySyllables.com. How Many Syllables, n.d. Web. 10 February 2026.

Learn a New Word

Wondering why radioactive is 5 syllables?   Contact Us!   We'll explain.

Syllable Rules

1.  What is a syllable?
2.  How to count syllables.
3.  How to divide into syllables.

More Grammar
Trending Words
Grammar Quiz
Is it then or than?

Take the Grammar Quiz

Syllables    Rhymes    Quiz

What rhymes with radioactive

2 syllables
  • active
    3 syllables
    4 syllables
    5 syllables
    Teacher of The Month
    Win $250 for your students.
    One prize is awarded to
    one teacher, every month.
    $Read the contest rules and apply
    Fun Fact
    Write swims on paper. Flip
    the paper 180°. It's still swims!
    !Get more facts
    Why Is
    Why is fire 1 syllable?

    ?Learn Why
    Do You Know
    when to use
    Whether and Weather?
    Find Out Here

    Parents, Teachers, StudentsDo you have a grammar question?
    Need help finding a syllable count?
    Want to say thank you?

    Contact Us!