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Why Soup Stays Hot in a Vacuum Bottle

3rd grade nonfiction passage about how a vacuum bottle works: 169 words, six questions, an answer key and vocabulary.

3rd grade nonfiction how a vacuum bottle works 169 words

Why Soup Stays Hot in a Vacuum Bottle

Pour hot soup into a thermos in the morning, and it can still be warm at lunch. Pour in a cold drink, and it can still be cold. How does one bottle do both?

Heat likes to move from warm places to cooler ones. It moves through metal and glass, and it moves through air. A thermos is made to slow that down.

A thermos has two walls, one inside the other, with a gap between them. Nearly all the air has been pumped out of that gap. A space with almost no air in it is called a vacuum. Heat has a very hard time crossing a vacuum, because there is hardly anything to carry it.

The walls are often shiny, too. A shiny surface bounces some of the heat back instead of letting it pass.

Last of all, there is a tight lid. It stops warm air from leaving the top of the bottle.

Together, these parts keep hot drinks hot and cold drinks cold for hours.

Questions

  1. What can a thermos keep both hot and cold? in the text

  2. Which way does heat like to move? in the text

  3. How many walls does a thermos have? in the text

  4. What is a space with almost no air in it called? in the text

  5. What job does the tight lid do? in the text

  6. Why does the gap between the walls help keep soup hot? think about it

Words to know

thermos
a bottle that keeps drinks hot or cold
vacuum
a space with almost no air in it
gap
an empty space between two things
surface
the outside or top layer of something
slow
to make something move more gently or less quickly
Share

One passage, three levels

The same topic and facts written three ways, so a mixed class can read and talk about one text. Each group’s sheet shows only a shape; the key says which is which.

● Easier · 143 words · Flesch-Kincaid grade 0.9

Pour hot soup in a thermos in the morning. At lunch, it is still warm. Pour in a cold drink. It stays cold. How does one bottle do both?

Heat likes to move from warm places to cool ones. It moves through metal and glass. It moves through air. A thermos slows this down.

A thermos has two walls. One is inside the other. There is a gap between them. Most of the air is pumped out of the gap. A space with almost no air is a vacuum. Heat has a hard time crossing a vacuum. There is hardly anything to carry it.

The walls are often shiny. A shiny wall bounces some heat back.

There is also a tight lid. It stops warm air from leaving the top.

All these parts keep hot drinks hot and cold drinks cold for hours.

▲ This passage · 169 words · Flesch-Kincaid grade 3

Pour hot soup into a thermos in the morning, and it can still be warm at lunch. Pour in a cold drink, and it can still be cold. How does one bottle do both?

Heat likes to move from warm places to cooler ones. It moves through metal and glass, and it moves through air. A thermos is made to slow that down.

A thermos has two walls, one inside the other, with a gap between them. Nearly all the air has been pumped out of that gap. A space with almost no air in it is called a vacuum. Heat has a very hard time crossing a vacuum, because there is hardly anything to carry it.

The walls are often shiny, too. A shiny surface bounces some of the heat back instead of letting it pass.

Last of all, there is a tight lid. It stops warm air from leaving the top of the bottle.

Together, these parts keep hot drinks hot and cold drinks cold for hours.

■ Harder · 180 words · Flesch-Kincaid grade 5.5

Pour steaming soup into a thermos in the morning, and it may still be warm when lunchtime arrives. Fill it with a cold drink, and that drink can stay chilly just as long. How can a single bottle manage both?

Heat has a natural tendency to travel from warm places toward cooler ones. It passes through metal and glass, and it also drifts through air. A thermos is designed to slow that movement down.

A thermos is built with two walls, one nested inside the other, and a gap between them. Nearly all of the air has been pumped out of that gap. A space containing almost no air is called a vacuum, and heat struggles to cross a vacuum because there is hardly anything there to carry it.

The walls are frequently shiny as well. A shiny surface reflects some of the heat back instead of letting it escape.

Finally, a tight lid prevents warm air from leaking out of the top of the bottle.

Working together, these features keep hot drinks hot and cold drinks cold for hours.

Download as one PDF

How to use it

  1. Press Read it big (or B) to put the text on the projector, or Full screen (F) to fill the whole screen.
  2. Ask the questions one at a time and use Show answer when the class has decided. A shows or hides every answer.
  3. Print student copy for the class, or Print with answers for yourself.

Ideas for class

  • Before reading, put thermos, vacuum, gap, surface and slow on the board with their meanings from the Words to know section and have students predict what the text will be about.
  • Read it aloud once while students follow along, then have them reread it alone or with a partner. At a calm 100 words a minute it takes about 2 minutes to read aloud.
  • Use the Read it big button (or B) to put the text on the projector, and Show answer on one question at a time so the class commits to an answer first.
  • Question 6 asks the reader to infer. Ask students to point to the words in the passage that led them to their answer.
  • Ask students to write one question the passage did not answer, then look for the answer in a book or on a classroom screen.
  • Print the student copy for independent work and keep the answer-key copy for yourself.

Related

Questions

What reading level is "Why Soup Stays Hot in a Vacuum Bottle"?

It was written for 3rd grade. It has 169 words and works out to a Flesch-Kincaid grade level of about 3.0. That is a formula's estimate from sentence length and syllables, and it is not a Lexile or a guided reading level, so check it against your students.

What do the questions ask?

There are six. 5 ask for something the text says directly and 1 ask the reader to work something out from clues. Each has an answer in the key, and the answers are written as a teacher would accept them, not as the only possible wording.

How long does it take to read?

About 2 minutes read aloud at 100 words a minute. For a one-minute fluency check, paste it into the fluency timer and use the word count.

Can I print it?

Yes. Print student copy gives the passage, the questions with lines to write on, and the word meanings. Print with answers gives the same page with the answers filled in. Both are made in your browser.

Is this passage from a published book?

No. It was written for Peabody Teach, so there is no book to buy and no login to read it.

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