Ask questions, use two sources and plan a short report.
Answer Key
Mateo's question
On family movie night, Mateo listened to the corn popping in the pot. "Why does popcorn pop?" he wondered. He decided to find out with a short research project, and his aunt Rosa offered to help.
1.
Mateo wants to learn why popcorn pops. Circle the two questions that will help him find out.
Which movie should we watch next week?What is inside a popcorn kernel?Is popcorn tastier with salt or with cheese?What happens to a kernel when it gets hot?How many bowls does my family have?
2.
Aunt Rosa helps Mateo look for sources. Sort them. Which ones can give him true facts?
a science book about how food cooksa funny poem about a popcorn partya cartoon about a kernel that talksa children's encyclopedia page about corna science center's web page about corna made-up story about a popcorn monster
Good source of facts
Not a source of facts
a science book about how food cooks
a children's encyclopedia page about corn
a science center's web page about corn
a funny poem about a popcorn party
a cartoon about a kernel that talks
a made-up story about a popcorn monster
Read two sources
Mateo found these two sources. Read both of them. Then answer the questions.
Source 1: How Popcorn Pops (from a science book)
1Popcorn is a special kind of corn. It grows on tall corn plants, but its kernels are small and very hard. Each kernel has a tough outer shell called the hull. Inside the hull is a starchy center that holds a small amount of water.
2When a kernel is heated, the water inside it turns into steam. Steam needs much more space than water does. The hull is so strong that the steam cannot get out. The steam pushes harder and harder on the inside of the shell. At last, the hull bursts open with a loud pop!
3As the hull breaks, the hot starch puffs out and cools into the white, fluffy shape you know. A popped kernel is many times bigger than a kernel that has not popped. Most other kinds of corn do not pop well, because their hulls are not strong enough to trap the steam.
Source 2: Popcorn Facts (from a science center website)
1Popcorn long ago. People in the Americas have grown and popped corn for thousands of years. Scientists who study the past have found very old popcorn kernels in some places.
2What makes it pop. Every popcorn kernel holds a little bit of water. Heat turns the water into steam, and the steam breaks the shell open.
3Why some kernels stay hard. Not every kernel in the pot pops. Some kernels are too dry inside to make enough steam. Others have a tiny crack in the shell, so the steam leaks out before it can push hard enough.
4Popcorn today. Today, popcorn is a favorite snack at movie theaters and fairs. Many families make it at home, too. People eat it plain or with toppings such as butter and salt.
3.
Finish Mateo's notes. Write one word from Source 1 in each blank.
Tough outer shell of a kernel: the hull Inside the shell: a starchy center and a little water When the kernel is heated, the water turns into steam
4.
Read Source 1, paragraph 2. Underline the sentence that tells why the steam stays trapped inside the kernel.
When a kernel is heated, the water inside it turns into steam.Steam needs much more space than water does.The hull is so strong that the steam cannot get out.The steam pushes harder and harder on the inside of the shell.At last, the hull bursts open with a loud pop!
5.
Good researchers keep track of where each fact came from. Sort each fact by the source that gives it.
Some kernels have a tiny crack that lets steam leak out.Heat turns the water in a kernel into steam.Most other kinds of corn do not pop well.A popped kernel is many times bigger than before.Each kernel holds a small amount of water.People have popped corn for thousands of years.
Source 1 only
Source 2 only
Both sources
Most other kinds of corn do not pop well.
A popped kernel is many times bigger than before.
Some kernels have a tiny crack that lets steam leak out.
People have popped corn for thousands of years.
Heat turns the water in a kernel into steam.
Each kernel holds a small amount of water.
6.
Mateo writes a note about Source 2, paragraph 3. Which note is in his own words and tells what the source says?
○A.Not every kernel in the pot pops.
○B.Kernels with too much heat may not pop.
●C.Dry or cracked kernels may not pop.
○D.Kernels that stay hard taste the best.
7.
Mateo wants to know how long people have been popping corn. Under which heading in Source 2 should he look?
○A.Popcorn today
●B.Popcorn long ago
○C.What makes it pop
○D.Why some kernels stay hard
8.
Mateo's research question is "Why does popcorn pop?" Which answer do both sources support?
●A.Trapped steam pushes until the shell bursts.
○B.Butter and salt make the hard shell crack open.
○C.Dry kernels pop better than kernels with water.
○D.The kernel grows on a tall plant, so it pops.
Plan a short report
Help Mateo plan a short report for his class. Use facts from both sources.
9.
Topic sentence: Write a sentence that tells what the report is about.
Popcorn pops because of the water hidden inside each kernel.
10.
Facts: Write two facts from the sources that explain why popcorn pops. Use your own words.
When a kernel gets hot, its water turns into steam. The strong hull holds the steam in until the hull breaks with a pop.
11.
Closing sentence: Write a sentence to end the report.
So the next time you hear popcorn pop, you will know that steam is breaking the shells open.