What Is in a Fart?: teacher key

Burps and Farts, grade 3 edition, written for 3rd grade. Gas is a mix of different gases, and only a small part of it smells. Find out what is in it and where air goes.

Read the book. Print this page for the key.

Questions and answers

1. What do most gases in a fart have?
   • No smell (answer)
   • A strong smell
   • A color
2. What smells like rotten eggs?
   • Nitrogen
   • Hydrogen sulfide (answer)
   • Oxygen
3. Who makes the smelly gas?
   • Microbes in the large intestine (answer)
   • Drinks with bubbles
   • Gum
4. Where does most swallowed air go?
   • It comes back up as burps (answer)
   • It turns into smell
   • It stays forever
5. Why does a fart not always smell bad?
   • Most gas has no smell (answer)
   • It is all hydrogen sulfide
   • Gas always smells like eggs
6. What does the word microbes mean here?
   • Tiny living things (answer)
   • Big animals
   • Loud sounds

Words

• sulfur: smelly stuff
• microbes: tiny living things
• lactose: milk sugar
• swallow: gulp down