Grade 7 April 27Th, 2020

Grade 7

April 27th, 2020

These and other resources are also available digitally on the HemetLearnsTogether.org website.

If a student has a 504 plan or receives mild/ mod SAI services, please refer to the accommodations packet. #HemetLearnsTogether

Grade 7 MATH Enrichment for the Week of 4/27/20

Dear Parents, Guardians and Students- Games to Play at home: At HUSD the safety and education of our students is of ● Tic-Tac-Toe ● Crazy 8 highest importance in times like this. We are excited ● Chess ● Connect 4 that during this time of being off of school that you are ● Rummy ● Solitaire continuing to trust us in your child’s education. We are happy to provide resources during this time including Skills to Practice Daily at Home: this packet of elected work in math that your child can ❏ Multiply and divide integers practice and sharpen previous learned skills that will ❏ Multiply and divide fractions have a lasting impact on their education. Each week you will be provided with the optional packet of work to complete in your free time at home. Continue to check hemetusd.org so that you can be provided with the most up to date information. It is our pleasure to continue to support your child during this time. #HemetLearnsTogether Sincerely, ~HUSD Instructional Support Math Team

Topics Covered in Try It At Home Game: this week’s work: Tangrams ❏ Find areas and After you have completed your tasks and checked your answer, carefully cut perimeters of shapes on a out page 3. square grid 1. Cut this page 3 ❏ Solve problems about out as carefully volume as you can as Family Challenge: possible Share with your family 2. You will notice tonight the answer to this that this shape question. started as a ● What is one thing that square. you have learned about 3. Use the shapes yourself during this time? that you have to ● What is one thing that see if you can you are missing about create the school? different shapes below. Try to spend no longer than 3-5 minutes per picture. 4. If you get stuck you can check on the site to learn the solution of each of these. Tank 3 1. The volume of water in the tank is 3,840 cubic inches (in ) . 24 × 16 × 10 = 3, 840

2. The water in the tank will be 20 inches (in) deep if that tank is turned so that it stands on one end. ● The volume of the water in the tank has not changed so divide the volume by the product of the two dimensions you have (length and width) to find the missing height. 3, 840 ÷ (12 × 16) = 20 5 5 ● Since the tank is 6 full, 6 of 24 inches is 20 inches. So the depth of the water is now 20 inches.

Square Elk 1. Area of E = 9 cm2 Area of L = 6 cm2 Area of K = 7 cm2 2. Perimeter of E = 20 cm Perimeter of L = 14 cm Perimeter of K = 10 + 6 × 1.4 = 18.4 cm

2 3. Area of N = 10 cm (The area inside the diagonal part of the N makes up 2 square units.) Perimeter of N = 16 + 2 × 2.34 = 20.68 cm

Tank This problem gives you the chance to: • solve problems about volume

A closed tank is 16 inches 24 inches long, 12 inches high, and 12 inches 16 inches wide. 10 inches It is ﬁlled with water to a depth of 10 inches. 24 inches

1. What volume of water is in the tank? Show your calculations.

2. How deep will the water be if the tank is turned so that it stands on one end?

Explain how you ﬁgured it out.

16 inches

12 inches

Page 7 Tank Test 6: Form A Square Elk This problem gives you the chance to: • find areas and perimeters of shapes on a square grid

DO NOT WRITE HERE

1. The word ELK is drawn on 1-centimeter squares. Find the area of each of the letters.

DO NOT WRITE HERE (The center square of the letter E is a 1-centimeter square.)

Area of E ϭ cm2

Area of L ϭ cm2

Area of K ϭ cm2

2. 1.4 cm

1 cm The length of the diagonal of a 1-centimeter square is DO NOT WRITE HERE approximately 1.4 centimeters. Use this measurement 1 cm to help you calculate the perimeter of each letter.

Perimeter of E ϭ cm

Perimeter of L ϭ cm

Perimeter of K ϭ cm

DO NOT WRITE HERE

06m_01-16_A03BAM 4 10/29/02, 11:35 AM 3. The letter N is drawn on 1-centimeter squares. The length of the diagonal of a rectangle measuring 1 centimeter by 2 centimeters is approximately 2.34 centimeters.

O O WIE HERE WRITE NOT DO

2.34 cm

1 cm

2 cm

Find the area and perimeter of the letter N. HERE WRITE NOT DO Show your calculations.

Area of N ϭ cm2

O O WIE HERE WRITE NOT DO

Perimeter of N ϭ cm

O O WIE HERE WRITE NOT DO

06m_01-16_A03BAM 5 10/29/02, 11:35 AM 7th Grade English Language Arts

for the week of April 27th, 2020 STUDENT LESSON SUMMARY Reading Public Notices ELA RI.7.5a, ELD PII.7.1

A public document is a text, available to the public, telling about local events or policies of an organization, such as a government service, school, business, or community group. Public documents often contain text features that tell you important information. Use the following steps to read and interpret public documents. Step 1: Find the title and headers of the public document. The title will tell you what the notice is about. Headers will tell you what a section of the text is about. Step 2: Decide whether the information in the public document affects you. Often a notice will tell about an activity you can take part in. Step 3: Find out who created the public document. Often there will be a logo, credit, or seal that shows who posted the notice in your community. Step 4: Take note of important details or instructions. What important details will affect readers, such as users of the policy or participants in the event? Are there actions the notice asks you to take? Some information may be accompanied by features such as boldfaced type, bulleted lists, or graphics that emphasize its importance. Step 5: Check for ways to find out more information. Most public documents, including signs, Web sites, and printed text, answer the obvious questions, but you may want more details. Look for a contact person, an e-mail address, or a phone number to find out more.

EXAMPLE: POSTED SIGN

Swimming Pool Rules and Regulations The following pool rules are designed to maintain a safe recreational area for all swimmers.

• All swimmers must shower before entering the pool. • No diving allowed. • Children under the age of nine must be supervised by an adult at all times. • Infants must wear swim diapers at all times. • No glass bottles or food allowed. • No radios allowed. • No flotation devices allowed in the pool.

Failure to follow the rules may result in loss of pool privileges.

Cape David’s Self-Guided Nature Trail More than 40 miles of pristine, sandy beach are protected within Cape David National Seashore. The national seashore comprises 40,000 acres of shoreline, salt marshes, dunes, and ponds, and a wide diversity of animals are supported by these habitats. Lighthouses, a life-saving station, dune shacks, and wild cranberry bogs provide a glimpse into Cape David’s past. As you hike along this self-guided nature trail with many scenic overlooks, please remember to follow

these rules: ©NatalieJean/Shutterstock Nature Trail Rules • Respect the flora and fauna that make their homes here. • Do not disturb animal habitats. • Do not litter.

“Take only photographs; leave only footprints.” —Cape David National Seashore www.capedavid.com

Practice and Apply: Use the public notice to answer the questions below.

If an Emergency Occurred, Would You Be Ready? The Citizens Council and the River Falls Ambulance Squad will again offer its free Basic First Aid Training class. The training, open to all River Falls residents, will prepare individuals to respond properly to typical home injuries and medical emergencies. This is also an excellent opportunity to become familiar with automatic external defibrillators (AEDs), which are now found in most public buildings and athletic facilities. The class will be taught by certified ambulance corps instructors. All attendees will receive Basic First Aid, CPR, and AED certificates. This training is offered as part of the Citizens Council’s continuing efforts to help residents cope confidently with emergencies of all kinds. This free instruction will be given on Saturday, July 12, from 12:00 p.m. to 5:00 p.m., at the River Falls Ambulance Squad Headquarters, 250 Clifton Road. Pre-registration is required in order to have enough training materials and instructors available. Register by phone at 555-6651 or stop by the Ambulance Squad Headquarters. For more information, please contact Marla Kalmbach at 555-6768. Sponsored by the Citizens Council of River Falls.

1. What is the title of this public notice?

2. Who sponsored this public notice?

3. What does the boldfaced information in the public notice tell you?

4. How could you find out more information about this event?

Practice and Apply: Use the public notice to answer the questions below.

Making the Connection for a Better Community The Grayfield Community Helpers program is excited to announce its partnership with Peterson Middle School to establish a new service project called Connect. Connect is an intergenerational project that matches youth and elderly people in a mutually beneficial relationship in an attempt to bridge the gaps between generations. Young volunteers will meet weekly with senior residents of the community to share ideas and experiences and occasionally to perform simple household tasks. Ideally, the Connect program will eliminate misconceptions that different generations have of one another. ©Lisa F. Young/Shutterstock Benefits for Volunteers • Provide an opportunity to do community service • Learn about issues and consequences of aging • Share life experiences and gain wisdom from older persons • Improve communication and social skills Benefits for Seniors • Decrease loneliness or anxiety • Increase social stimulation A volunteer for the Grayfield Community • Share life experiences and teach history Helpers program assists a senior resident. If you are interested in the Connect program, ask Mrs. Manning in the guidance office for an application. Volunteers will receive special training from the Grayfield Community Helpers before beginning their service work. For more information, call Gloria Mazzi of Grayfield Community Helpers at 555-7878.

1. How does the title of this notice hope to attract volunteers?

2. Why is the photograph and caption included?

3. What information do the headers and bulleted lists provide?

4. Which of the benefits of the program for young people do you think would be the most valuable? Explain.

Practice and Apply: Read the following business memo. Then answer the questions below.

GRAYFIELD CORPORATION MEMORANDUM DATE: June 11, 2014 TO: All Employees FROM: Rhoda Maxwell, Human Resources Director SUBJECT: EMPLOYEE PARKING The four parking spaces directly in front of the main entrance are for visitors only. These spaces are clearly marked VISITORS. Employees of the Grayfield Corporation may not park in these places. All employees must park in the Green Street parking lot behind the building. Thank you for your cooperation in this matter.

1. When was this memo written?

2. Who will receive copies of this memo?

3. Why is the boldfaced text in the public notice important?

4. What is the main purpose of this memo?

Copyright © by Houghton Mifflin Harcourt Publishing Company California Standards Support and Enrichment 5 Reading Public Notices 7th Grade History for the week of April 27, 2020 7th Grade History - Distance Learning Enrichment Activities Week of April 27, 2020

First Crusade Lessons Central Historical Question: What happened when Crusaders entered Jerusalem during the First Crusade?

First Crusade Materials: In 1095, Pope Urban II launched the First Crusade, calling forth knights and peasants from across • First Crusade PowerPoint handouts Western Europe to march against Muslim Turks in • Documents A-C the Byzantine Empire and ultimately “re-conquer” • Reading Guide the holy city of Jerusalem. In this lesson, students compare Christian and Muslim perspectives of the Instruction : First Crusade by analyzing different accounts of the s siege of Jerusalem. 1. Introduction: Use PowerPoint slides to review background information on the First Crusade. a. Highlight: i. Slide 2: In 1095, Byzantine Emperor Alexios I contacted Pope Urban II about the threat of Turkish armies against Constantinople and the Fatamid Muslim’s control of Jerusalem. In November, 1096, Pope Urban II considered Alexios’ plea at the Council of Claremont, and called for a crusade against the Muslim Turks.

ii. Slide 3: Large numbers of nobles, knights, and peasants responded to Urban II’s call. In 1096, crusading armies set out to Constantinople.

iii. Slide 4: Prior to the Crusades, there was infighting between Sunni Seljuk Turks, who had conquered a lot of land and the Shi’ite Fatamid Caliphate. Just before the First Crusade, the Fatamids captured Jerusalem from the Seljuk Turks. Knowing the Crusaders were coming, the Fatamids expelled all Christians from Jerusalem.

iv. Slide 6: Crusading armies arrived at the gates of Jerusalem in the summer of 1099. After a failed attempt to take the city, the army broke through the city walls on July 17. They took the city after a costly battle that some estimate involved 100,000 casualties.

v. Slide 7: Christians believed they were fighting the Crusades in the name of Jesus to take back the place of his birth from infidels. Muslims believed they were defending land that was theirs. From their perspective, Christians were brutal invaders.

vi. Slide 8: View this week’s historical question. This week, we will look at 3 documents written from Christian and Muslim perspectives to investigate the question: What happened when Crusaders captured Jerusalem during the First Crusade?

STANFORD HISTORY EDUCATION GROUP sheg.stanford.edu 2. Introduce/review skills of sourcing and corroboration. Points to highlight:

a. Historians create historical accounts, in part, by comparing multiple documents and perspectives of different people. Focusing on perspective is important because it helps evaluate possible biases and the trustworthiness or reliability of a document.

b. Checking the source information on a document is a good place to begin evaluating perspective. Before reading, ask yourself: Who wrote this document? When was it written? What type of document is it? Based on this information, see if you can go even further by trying to determine why the document was written, and make a prediction on what the document might be about.

c. While reading the document you can continue analyzing perspective. Pay close attention to the author’s argument or narrative and the words and phrases they use to make their argument or describe their version of history. Ask yourself: How does this document make me feel about this topic? What words or phrases does the author use to describe people and events?

d. Our task this week is to compare and contrast 3 documents from the First Crusade, and in particular the capture of Jerusalem. You are going to explore different perspectives on this event while considering what happened when the Crusaders captured Jerusalem.

3. Get out Document A along with Reading Guide. a. Highlight the document’s source to establish when, where, and by whom this document was created. b. Predict what Raymond d’Augiliers might say about the capture of Jerusalem. c. Read the document. While you read, underline words and phrases that make you think this document is written from a Christian Crusader’s perspective. 4. Get out Document B. a. Highlight the document’s source to establish when, where, and by whom this document was created. b. Predict what Ibn al-Athir might say about the capture of Jerusalem. c. Read the document. While you read, underline words and phrases that make them think this document is written from the Muslim perspective.

STANFORD HISTORY EDUCATION GROUP sheg.stanford.edu 5. Corroboration a. Identify 1-2 similarities and 1-2 differences between the 2 documents 6. Get out Document C. You are going to read a third document without any source information. Your task is to read the document, consider how it compares to the others and try to determine if the document comes from a Muslim or Christian writer. a. Read the document and underline words, phrases, or sentences that might indicate the perspective of this document. b. Draw on evidence from all 3 documents to decide if Document C is more similar to Document A or B. c. Draw from evidence in the document to decide if it is written from a Muslim, or Christian perspective. d. View the source information of Document C (final slide in the PowerPoint).

This document is from the French chaplain Fulcher of Chartres, a Christian, who participated in and wrote first-hand accounts of the First Crusade. In this excerpt, written sometime between 1100 and his death in 1127, he describes the Crusaders taking Jerusalem.

7. Reflection Questions a. Based on these sources, what happened when Crusaders entered Jerusalem during the First Crusade? b. What are the primary similarities and differences of these documents? c. Are these trustworthy accounts? Why or why not? d. What other primary source documents might you read to better answer today’s historical question?

Citations Document A Raymond d'Aguiliers, “The Siege and Capture of Jerusalem,” in The First Crusade: The Accounts of Eyewitnesses and Participants, ed. August. C. Krey (Princeton: 1921), 257-62.

Document B Ibn Al-Thir, “The Franks Conquer Jerusalem,” in Arab Historians of the Crusades, Francesco Gabrieli, translated by E.J. Costello (Berkeley: University of California Press, 1969), 10-11.

Document C Fulk (or Fulcher) of Chartres. (?1100-1127). Gesta Francorum Jerusalem Expugnantium [The Deeds of the Franks Who Attacked Jerusalem], in Parallel Source Problems in Medieval History, eds. Frederic Duncalf, F. and August Krey (New York: Harper & Brothers, 1912), 109- 115. Retrieved October 16, 2012, from: http://www.fordham.edu/Halsall/source/fulk2.asp

STANFORD HISTORY EDUCATION GROUP sheg.stanford.edu

Document A: Raymond d’Aguiliers (Modified)

Raymond d'Aguiliers was an eyewitness to the First Crusade. He followed the crusading armies army to Jerusalem and wrote a history of his experiences. The passage below is a modified excerpt from his account of the Crusaders’ siege of Jerusalem that he wrote sometime after the First Crusade.

Finally, our men took possession of the walls and towers, and wonderful sights were to be seen. Some of our men (and this was more merciful) cut off the heads of their enemies; others shot them with arrows, so that they fell from the towers. It was necessary to pick one's way over the bodies of men and horses. In the Temple of Solomon, men rode in blood up to their knees and bridle reins. Indeed, it was a just and splendid judgment of God that this place should be filled with the blood of the unbelievers, since it had suffered so long from their blasphemies. Some of the enemy took refuge in the Tower of David, and, petitioning Count Raymond for protection, surrendered the Tower into his hands.

How the pilgrims rejoiced and exulted and sang a new song to the Lord! On this day, the children of the apostles regained the city and fatherland for God and the fathers.

Source: Raymond d'Aguiliers, “The Siege and Capture of Jerusalem,” exact date unknown.

Vocabulary

Temple of Solomon: Temple of Solomon was a Jewish temple, first destroyed by the Babylonians and then by the Romans in 70 CE. In the 600s CE, Muslims built the Al-Aqsa Mosque and the Dome of the Rock on the same site. bridle reins: headgear and rope used to control a horse blasphemies: speech or behavior that is inappropriate towards God.

STANFORD HISTORY EDUCATION GROUP sheg.stanford.edu Document B: Ibn al-Athir (Modified)

Ibn al-Athir (1160-1233) was an Arab historian who wrote a history of the first three crusades, though he only witnessed the third one. The passage below is a modified excerpt from his account of the siege of Jerusalem during the First Crusade.

Jerusalem was taken from the north on the morning of July 15, 1099. The population was put to the sword by the Franks, who pillaged the area for a week. A band of Muslims barricaded themselves into the Tower of David and fought on for several days. They were granted their lives in return for surrendering. The Franks honored their word, and the group left by night for Ascalon. In the Al-Aqsa Mosque the Franks slaughtered more than 70,000 people, among them a large number of Imams and Muslim scholars, devout men who had left their homelands to live lives of religious seclusion in the Holy Place. The Franks stripped the Dome of the Rock of more than forty silver candelabra and more than twenty gold ones, and a great deal more booty. Refugees reached Baghdad and told the Caliph’s ministers a story that wrung their hearts and brought tears to their eyes. They begged for help, weeping so that their hearers wept with them as they described the sufferings of the Muslims in that Holy City: the men killed, the women and children taken prisoner, the homes pillaged.

Source: Excerpt from Ibn al-Athir’s “The Complete History,” written in 1231.

Vocabulary

Al-Aqsa Mosque: see note on Temple of Solomon above. Franks: Christians Imams: Islamic leader devout: very religious candelabra: large candlesticks Caliph: Islamic ruler pillaged: rob violently

STANFORD HISTORY EDUCATION GROUP sheg.stanford.edu Document C: ?

At the noon hour on Friday, with trumpets sounding, amid great commotion the Franks entered the city. . . Men joyfully rushed into the city to pursue and kill the nefarious enemies, as their comrades were already doing. Many of our enemies fled to the roof of the temple of Solomon, and were shot with arrows, so that they fell to the ground dead. In this temple almost 10,000 were killed. Indeed, if you had been there you would have seen our feet colored to our ankles with the blood of the slain. But what more shall I relate? None of them were left alive; neither women nor children were spared.

Vocabulary nefarious: wicked or criminal

STANFORD HISTORY EDUCATION GROUP sheg.stanford.edu First Crusade Reading Guide

Document A: Raymond d’Aguiliers 1) Read Document A. While you are reading, underline any words, phrases, or sentences that indicate that this document was written from a Crusader’s perspective.

2) Share with your partner what parts of the document you underlined, and why you underlined those parts.

Document B: Ibn al-Athir 1) Read Document B. While you are reading, underline any words, phrases, or sentences that indicate that this document was written from a Muslim perspective.

2) Share with your partner what parts of the document you underlined, and why you underlined those parts.

Corroboration Identify 1-2 similarities and 1-2 differences of these accounts Similarities

Differences

STANFORD HISTORY EDUCATION GROUP sheg.stanford.edu

Document C: ?

1) Read Document C. While you are reading, underline any words, phrases, or sentences that might indicate the perspective of the document’s author.

2) Which document is Document C more similar to?

Document A Document B

Explain your choice. Use 2-3 specific examples from the documents in your explanation:

3) Do you think this document is from a Christian or Muslim perspective? Why?

STANFORD HISTORY EDUCATION GROUP sheg.stanford.edu The First Crusade Pope Urban II

• In 1095, Byzantine Emperor Alexios I contacted Pope Urban II about the threat of Turkish armies against Constantinople and the Fatamid Muslim’s control of Jerusalem

• In November 1096, Pope Urban II considered Alexios’ plea at the Council of Claremont, and called for a crusade against the Muslim Turks. Pope Urban II at Claremont

2 Crusaders

• Ten of thousands of peasants, nobles, and clergy responded to Urban II’s call.

• In the spring and summer of 1096, armies of Crusaders departed from Western Europe for Constantinople. Peter the Hermit Leading an army of crusaders

3 Shi’ite Fatamids

• Prior to the Crusades, there was infighting between Sunni Seljuk Turks, who had conquered a lot of land and the Shi’ite Fatamid Caliphate.

• Just before the First Crusade, the Fatamids captured Jerusalem from the Seljuk Turks.

• Knowing the Crusaders were coming, the Fatamids expelled all Christians from

Jerusalem. 4 Capture of Jerusalem

• Between 1096 and 1099, Crusader armies made their way to Jerusalem, engaging in several major battles with Turkish forces.

• On July 17, 1099, Crusaders took the city of Jerusalem, after a long and costly siege. Some historians estimate the number of casualties at Capture of Jerusalem 100,000. 5 Map of the First Crusade

6 Perspectives

• Christians believed they were fighting the Crusades in the name of Jesus to take back the place of his birth from infidels.

• Muslims believed they were defending land that was theirs. From their perspective, Christians were brutal invaders.

7 Central Historic Question

What happened when Crusaders entered Jerusalem during the First Crusade? Document C

9 7th Grade Science - Thermal Energy Week 04/27/20

Reading: ● Annotate the article: The transfer of thermal energy can occur in three ways ○ Underline important ideas ○ Circle important words ○ Put a “?” next to something you want to know more about ○ Answer questions at the end of the article

Activity: ● Build an insulated shoebox ○ Insulated Shoebox

Writing: ● Read the article: Cold House, Hot House, Green House ○ Answer the writing prompt at the end of the article.

Ciencia de Séptimo Grado - Energía Termal

Semana de 04/27/20

Lectura: ● Anotar el artículo: The transfer of thermal energy can occur in three ways ○ Subráye ideas importantes ○ Circúle palabras importantes ○ Ponga un "?" junto a algo que usted quiera saber más ○ Conteste las preguntas al final del artículo

Actividad: ● Construya una caja insulada de zapatos ○ Insulated Shoebox

Escritura: ● Lea el artículo: Cold House, Hot House, Green House ○ Responda la pregunta al fin del artículo. The transfer of thermal energy can occur in three ways By National Geographic Society on 02.13.20 Word Count 1,088 Level MAX

Image 1. Radiation is one way that heat transfer occurs. All objects radiate some amount of heat as electromagnetic waves, even humans. Hotter objects, like light bulbs and campfires, radiate higher-energy light that we can see. Photo by National Geographic

Thermal energy comes from the movement of atoms. Since atoms make up the entire known universe – and it is impossible to reach absolute zero (minus 273.15 degrees Celsius or minus 459.67 degrees Fahrenheit), the theoretical temperature at which even atoms are frozen in place – everything has thermal energy. Whether they are zipping around in a gas or barely shivering in a solid, atoms are constantly moving.

Although all objects have thermal energy, they do not all have the same amount. Extremely hot objects such as the sun have vastly more thermal energy than cold objects like ice. However, the sun can transfer some of its thermal energy to ice, which is what causes an ice cube to melt on a warm, sunny day. The movement of thermal energy from a hotter object to a colder object is called heat transfer.

This article is available at 5 reading levels at https://newsela.com. Heat transfer can happen in three different ways: through conduction, convection, and radiation. All three forms of heat transfer happen constantly in daily life, and in fact, heat transfer is essential to life itself.

Conduction

Conduction requires contact between the objects involved. Solids, liquids and gases can all conduct heat. As with any form of heat transfer, there must be a temperature difference for conduction to happen, and thermal energy is always transferred from the hotter object to the colder one. Once the objects reach the same temperature, the heat transfer stops. This is called thermal equilibrium.

On a microscopic level, conduction happens when particles bump into each other. Consider a cold metal spoon in a hot cup of coffee: The molecules in the coffee are moving freely and the metal molecules in the spoon are vibrating. Since the coffee is hotter than the spoon, its molecules are (overall) moving more. As they bump up against the spoon, the coffee molecules transfer some of their energy to the spoon molecules. As these collisions keep happening, the spoon gets warmer and the coffee gets slightly cooler until both are the same temperature.

Once the spoon and the coffee reach this thermal equilibrium, the particles do not quit bumping against each other. They continue transferring energy back and forth, but there is no longer a net flow of thermal energy in one direction. The two objects remain at the same temperature unless acted on by something else that adds or subtracts heat from them. In most cases, that something is the air in the room, which draws heat from the coffee. Eventually, if allowed to sit, the coffee cup, the coffee, and the spoon will all be the same temperature as the ambient air. They are once again at thermal equilibrium, but this time with their surroundings.

Some materials conduct heat better than others. Materials that conduct heat well, like metals, are called conductors, while materials that do not conduct heat well, like wood and plastic, are called insulators. This is why people often choose wooden or plastic-handled spoons when cooking – they do not get nearly as hot as metal spoons.

Convection

Heat transfer via convection happens only within fluids, like liquids and gases. Fluids are not very good conductors, so they transfer heat mostly by convection. Consider a pot of water heating on a stove: The heat source –the stove burner – is beneath the pot, so water near the bottom of the pot heats up first. Fluids expand when they heat up, so the water near the bottom becomes less dense. The difference in density between water at the bottom and at surface produces circulation currents. Hotter, less-dense water begins to rise and displace colder, denser water, which then sinks to the bottom where it is heated and begins to repeat the cycle. As time goes on, more of these circulation currents develop, transferring heat throughout the liquid. These convection currents can be easily observed when boiling rice in water.

Convection currents also allow heated air to circulate through a room. The phrase "heat rises" should really be "heated air rises," since it is the heated air molecules that are rising and circulating.

Convection plays a large role in moving plate tectonics. Earth's solid outer layer, the lithosphere, sits on top of a semi-molten layer called the asthenosphere. The asthenosphere is heated from

This article is available at 5 reading levels at https://newsela.com. even-hotter regions below, so – just like a pot on a stove – this heat source creates slow, but massive, convection currents within the asthenosphere, which causes some of the movement of Earth's tectonic plates.

Radiation

To understand radiant energy, we need to understand electromagnetic waves. Light can act as both a particle and a wave, and when it acts as a wave, the waves are referred to as electromagnetic. These waves can have different amounts of energy based on how fast they vibrate up and down. Fast-vibrating (high-frequency) waves have more energy than slow-vibrating (low- frequency) waves. All of these waves exist on the electromagnetic spectrum, with low-energy waves on one end and high-energy waves on the other. Humans can only see light waves in a specific part of this range, called the visible spectrum.

Radiation is the transfer of heat via electromagnetic waves. All objects radiate some amount of heat as electromagnetic waves, even humans. Humans radiate energy as infrared light, which is too low- energy for us to see. However, we still feel it as heat – in fact, infrared radiation is commonly referred to as "heat rays." Hotter objects, like light bulbs and campfires, radiate higher-energy light that we can see.

Radiation can even transfer heat through the vacuum of space. The sun radiates heat through millions of miles of empty space down to Earth. Because the sun has so much thermal energy, it radiates many kinds of electromagnetic waves, including infrared light, visible light, ultraviolet light, and X-rays. Ultraviolet light and X-rays are high-energy forms of light that we cannot see.

This article is available at 5 reading levels at https://newsela.com. Quiz

1 Which characterization accurately describes BOTH conduction and convection?

(A) Both only occur when currents are created by different densities.

(B) Both only occur when there is contact between two solid objects.

(D) Both can involve liquids or gases, and need a temperature difference in order to occur.

2 Which option BEST explains how thermal equilibrium interacts with heat transfer between particles?

(A) Thermal equilibrium stops the transfer of energy in just one direction when both objects reach the same temperature, but allows their particles to continue transferring that energy back and forth.

(B) Thermal equilibrium always transfers energy from the hotter object to the colder one, and increases the energy and speed of moving particles in both objects as the temperature decreases.

(C) Thermal equilibrium helps the transfer of energy between the particles of some materials better than others, but always stops the transfer of energy in materials like plastic and wood.

(D) Thermal equilibrium quickly transfers energy back to the particles of the object that was originally hotter, and requires that the particles in both objects have reached equal energy and density.

3 Which statement BEST explains the advantage of including Image 2 in the article?

(A) The image illustrates the temperature differences between hot and cold water using red and blue arrows familiar to most readers of the article.

(B) The image illustrates the circulation of hot water rising and cold water sinking during convection using the example that is described in the article.

(C) The image illustrates the effects of the heat transfer occurring with the air above an object in addition to the convection that is happening inside it.

(D) The image illustrates the way that the asthenosphere is heated from even hotter regions below it to create slow but massive convection currents.

4 How does Image 3 in the section “Radiation” support the reader's understanding of electromagnetic waves?

(A) It uses colored stripes to demonstrate that UV light and X-rays are low-energy forms of light.

(B) It indicates the reactions that take place within the human eye for visible light to be seen.

(D) It shows the differences in energy between light acting as a particle and light acting as a wave.

This article is available at 5 reading levels at https://newsela.com. Answer Key