keckscience.weebly.com€¦ · Web view: There are a number of different forms of water. Some are salt water—oceans, seas, bays, and gulfs and some lakes, while others are fresh

Water—Middle School—8 Lessons

Lesson LessonObjective

PriorKnowledge Content—Activities Closing

1 The purpose of today’s lesson is to look at the oceans, major rivers, lakes, gulfs, bays and seas and for youth to locate them around the world.

What are the forms that water can take?

Is this true of other substances as well?

What is a bay?

What is a gulf?

What is a river?

What is a lake?

Is it possible for a lake to be salt water? What makes you think so?

Background Information: There are a number of different forms of water. Some are salt water—oceans, seas, bays, and gulfs and some lakes, while others are fresh water—rivers and lakes (and of course their diminutive forms—creeks, brooks, ponds, puddles, etc.) There are 4 oceans, 10 major rivers, 10 large lakes and 10 gulfs, bays, and seas. These bodies of water can either be found on the land (fresh water, sometimes salt) or surrounding the land (oceans, bays, gulfs, and seas.)

Mini Investigation: Freezing WaterQuestion: Does water expand when it freezes?

1. Have youth vote yes or no and explain why each made the choice he/she did2. Fill the milk carton to the top with water and place it in a freezer. Wait until it is completely

frozen and see if the ice is coming out of the milk carton. (You will have to wait for tomorrow to find out.)

Activity: Waters of the WorldWhat you will need:

Maps of the world—blank (11x17 paper size) Reference Maps of the World print on 11x17 paper (if globes are available you may use those) Waters of the World Fact Cards (2-3 sets per team. Cut out cards in advance or have students

cut them out when you distribute the sheets.)

What you will do:1. Divide the class into 3 teams2. Distribute the atlas pages, world maps, and a globe (if you have one)3. Distribute the Waters of the World Fact Cards. (cut in advance or have students cut them)4. There are 4 different cards each with a different category.

1. Oceans2. Rivers3. Lakes4. Seas, Bays and Gulfs

5. Give each team the opportunity to study the Fact Cards, locate the body of water on the maps, globe or atlas for 20 minutes

6. Reassemble the teams, collect the Bodies of Water Cards, the atlas pages and other study materials, and explain that they are going to play the Water of the Worlds Game

7. Each team lines up in a single line (3 lines)8. Player from the first team comes forward and selects one of the four types of water (Oceans,

Review today’s lesson by simply recapping what was done.

Reflect on what you’ve learned—was it a confirmation, an adjustment, or a new learning.

Debrief:In what ways was this lesson active?

In what ways was this lesson collaborative?

were you surprised id anything surprise you as you were locating the different bodies of water?

Were you surprised to find that some lakes can be salty? What makes this happen?

Water-Middle School: Lessons 1-8 Page 1



Rivers, Lakes, or Seas, Gulfs and Bays9. The player has 2 choices.

1) student can ask for the body of water and then he/she gives the description or2) student can ask for a clue (PL reads a small part of description) and student can guess which body of water it is.

10. If player does not know the answer, he/she may call a Life Line and ask a person on his/her team for help.

11. Player must then state his/her answer. If the player is successful, he/she wins one point for the team—if not then the next team can “steal” the point by answering the question; if the second team can’t answer correctly, then the third team gets one chance.

12. Play continues until one team has scored 7 points and all teams have had an equal number of turns.

2 The purpose of today’s lesson is to show youth where the major rivers are in North America. These are the rivers that provide our water for drinking and crops and are essential to our lives.

What are some rivers that you know about?

In your opinion, why would people settle around rivers?

What is the continental Divide?

Where is it?

Do you live on the west or the east of the Divide?

Background Information: (handout has background information plus a Q&A about Water) Historically, societies and civilizations have grown up around rivers and the water supply that they provide. Water is essential for survival. Rivers provide a source of water to drink, water crops, a place to bathe and clean clothes, and transportation from one place to another. Whether you are looking at the Tigris/Euphrates River in the Mideast which was the home of two early civilizations or the number of Indian tribes and early settlements in the United States, on every continent, rivers have been the backbone of civilizations. Rivers are always flowing to the sea where fresh water joins with salt water. Some rivers flow north to south, others flow east and west. Rivers all have a source, a place in which they begin the flow to the sea. Many of the larger rivers have a tributary (or more than one) which is a smaller river that joins the larger river, making it even larger. In the United States the Rocky Mountains acts as a Continental Divide. On the east of the Rocky Mountains, the rivers flow to the east and the south, draining the rain and snow. On the west side of the Rockies, the rivers flow south and west, toward the Pacific. The Continental Divide acts as a divide for the country.

Mini Investigation: Water and HeatWhat you will need: 2 identical containers

Question: Does water absorb heat?1. Write the question, “Does water absorb heat?” on the board.2. Have youth vote yes or no and explain why each made the choice he/she did3. On a sunny day, put equal amounts of water (of the same temperature) in containers.4. Put one container in the sun and the other in the shade.5. Check the temperature every half hour for several hours.6. Discuss your findings.





In what ways was this lesson meaningful?\

Of the rivers you found, which one most impressed you? For what reason?




Activity: Rivers of North AmericaWhat you will need:

7. An Introduction to Rivers handout8. Maps of North America—(print in color on 11x17 inch paper)9. Rivers of North America cards (cut out in advance or have students do so)10. 3” x 5” cards (3 for each group)

What you will do:11. Divide youth into pairs12. Provide each pair with the handout - An Introduction to Rivers, a Map of North America and a

set of Rivers of North America cards13. Explain that youth should read through the Rivers of North America cards and locate the rivers

on the cards on the map of North America14. After reviewing the cards and locating the rivers, each group should write 3 questions on one

side of the 3” x 5” card, flipping it over and providing the answer.15. When all groups have completed the cards (and the review) bring the group back together16. Explain that they are now going to play the game, “Take My Card”17. Explain that each pair will move around and stop another pair and ask the pair one of the

questions on the cards they created. If the other pair can answer the question correctly, that pair gets the card. If not, then the pair gets to keep its card.

18. Pairs reverse roles applying the same rules19. Once both pairs have asked one another a question and either kept or lost the card, the pair

moves on to the next pair and repeats the process20. When time is called (somewhere between 10-15 minutes) stop the game and determine who

has the largest number of cards. If there is a tie, bring the pairs up involved with the tie, and using the question cards they have collected, state the question, and the first pair to provide the correct answer wins a point.

21. Tie is broken when after each round one pair has more points that the other pairs

In earlier times, before air travel, it was said that if you controlled the rivers you controlled the country. What does that mean? Why would that be so?

3 The purpose of today’s lesson is to learn more about water in its three forms, and the way water is or is not absorbed by things.

What elements can be found in water?

What does it mean to absorb?

Name something that

Background Information: A water molecule is made up of two hydrogen atoms (H) and one oxygen atom (O) that have combined. This molecule is written in this way: H2O. This scientific notation is recognized world-wide as water. Like other elements, water can come in three forms: steam, liquid (the water we drink), and ice. The measurement of heat scale known as Fahrenheit is based on when water freezes and becomes ice (32̊ ), boils and becomes steam (212 ̊ ) and remains a liquid (33 ̊ - 211 ̊ ).

Mini Investigation: Absorbing WaterWhat you will need: strips of cotton, metal, leather, paper, plastic, wood, and other items available


Reflect on what you’ve learned—was it a confirmation, an adjustment, or a new




absorbs water.

Name something that does no absorb water?

What are the forms that water takes?

What connection does water have with the Fahrenheit scale?

Question: Which materials absorb water?1. Write the question, “Which materials absorb water?” on the board.2. Have students vote yes or no and explain why each made the choice he/she did.3. Have strips of cotton, metal, leather, paper, plastic, wood, and other items available4. Fill a small container with water and place each objects in the water with one end in the water

and the other end over the container.5. After 5 minutes checks to see which strips absorbed water.

Activity: Water Forms and MoleculesWhat you will need:

Activity: Water forms and Molecules Handout Ice (2 sizes—cubes, shaved, pebbled) Two 4 ounce cups Two 2 ounce cups 3” x 5” card 2 colors of gumdrops (suggest red and white) Toothpicks (round)

What you will do:1. Divide students into pairs and distribute the Activity handout.2. Pair should take two 4 ounce and two 2 ounce cups, labeling one 4 ounce and one 2 ounce cup

with the word “cube”, and one of the 4 ounce and one of the 2 ounce cups shaved or pebbled3. Explain to pairs that they will fill one 4 ounce cup with ice cubes and another with shaved or

pebbled ice.4. Explain that the pair should predict which type of ice will melt the most quickly and WHY they

believe that this is the case5. Pair should write the prediction down on the 3” x 5” card6. Every 10 minutes, youth will pour the water from the melted ice in the 4 ounce cup into the 2

ounce cup labeled with either cube or shaved/pebbled—this process should be repeated every 10 minutes and at the end, pair will determine if their prediction was correct or incorrect by determining which 2 ounce cup has the most liquid.

7. Part II: While the ice is melting, pairs should build 4 water molecules by using the toothpicks and gum drops

8. Once the pairs have created the water molecules, they should explain what they have done to another pair, and then divide the “water molecules” between the pair (eat and enjoy)

9. Have each pair share out the results of their ice melting investigation

learning.



In what ways was this lesson meaningful?

4 The purpose of this lesson is to discuss the

Is it possible that you drink the same water

Background Information: (see handout) You drink the same water that the dinosaurs drank. How can that be? As you study the water cycle try to figure this out. Understanding the water cycle is important to realizing how important water is to the earth. Water is the most common substance on earth. Without





water cycle and how it is continuously occurring?

that the dinosaurs drank? What is the reason for your answer?

What is a meant by a cycle?

What is the water cycle?

In your opinion why do some things sink and other things float?

What about large ships that weigh tons and tons—how can they stay afloat?

water there would be no life. Water is the only substance on earth that is found in three forms, as a liquid, as a solid, and as a gas (water vapor/steam). The water cycle helps to explain this phenomenon. The water cycle is the ever-ending circulation of water. As the water in the oceans is evaporated by the sun it rises as invisible vapor which then falls back to earth in the form of rain, snow, or other forms of moisture. This is precipitation and mainly falls into the ocean. What doesn’t fill in the ocean falls on the land. Eventually this water returns to the ocean only to be evaporated and the cycle starts all over again.

The purpose of this experiment is to see the water cycle. When you have the hot water in the bottom of the bottle and then seal the container and place the funnel end down, the hot water will evaporate and “sweat” along the top of the inverted funnel. When you add the ice it will cool the inverted funnel, causing the bottle to “rain” back into the water below. The hotter the water in the beginning, the better.

Mini Investigation: Sink or Float?What you will need: cork, plastic objects, wire, lump of clay and other objects

Question: Does water expand when it freezes?1. Write the question on the board and under the question draw 2 columns. Label one sink and

one float.2. Have youth vote yes or no and explain why each made the choice he/she did3. You will need cork, plastic objects, wire, lump of clay and other objects4. Fill a pan with water. Put the objects you have in the water.5. Keep a record of which ones floated and which ones sink

Activity: Water CycleWhat you will need:

The Cycle of Water Worksheet Clear 2 liter soda bottle cut as shown on right

(1 for each group of youth) Warm water Cellophane or duct tape Ice cubes

Preparation: This needs to be done BEFORE giving the bottle to students:1. Cut the bottle top off, about 5” from the top—2. Do not discard the top half (leave cap on)

What you will do:1. Have students work in pairs





What surprised you about creating a water cycle?

Did you actually get to see it begin to “rain”?

If water recycles over and over, what does that suggest to you about the way we should treat the water we have?




2. Distribute all materials and the Cycle of Water Worksheet3. Pour the cup of very warm water (the warmer the better) into the soda bottle cylinder.4. Make sure the cap is screwed tightly onto the funnel top of the soda bottle5. Use tape (cellophane or duct tape) and wrap it around the widest portion of the funnel (this will

help to form a tight seal between the funnel portion and cylinder portion of the bottle.6. Place the funnel portion of the bottle upside down into the soda bottle cylinder.7. Place bottle under direct sunlight for minimum of 5 minutes8. Predict what you think will happen (answer: nothing at all to a small amount of condensation

forming on inside of cylinder and funnel)9. Observe the inner surface of the cylinder and the bottom of the funnel10. Now place 2-3 ice cubes into the funnel and wait 5 minutes.11. Predict what you think will happen next (moderate to large amount of condensation will form on

the funnel and drip back into the cylinder.)12. Describe what is happening.

5 The purpose of today’s lesson is to encourage youth to think about water and how the water cycle works and in fact could be threatened by pollution.

What are the three forms of water? Please give examples of each.

What is a pollutant?

What can be done to limit the number of pollutants in our water?

Background Information: The states in which water exists—solid, liquid, and gas—are often referred to as phases. As heat is added or removed, water goes through a phase change. In its solid phase, water molecules are structure and orderly, in its gaseous phase water molecules lack structure and order. In nature, the energy, or heat of the sun causes water to evaporate into its gaseous or vapor, phase. Likewise, when we boil water over a burner we are causing it to change from a liquid to a gas. The process by which a substance changes from a liquid to a gas is called evaporationWater is continuously being heated and cooled—evaporating, condensing, freezing—depending on the environmental circumstances. As water travels its ever-ending cycle between earth and the sky, it encounters and mixes with a variety of substances. Some of these substances are pollutants in the sense that they are harmful to living things. Pollution can result both from natural sources and human activities.Fortunately, through the water cycle, nature provides a variety of mechanisms for cleaning water. For example, evaporation is a natural water cleanser. When water evaporates, it leaves most dissolved substances and waste materials behind. Pollutants can also be filtered out when water moves through soil. Some pollutants settle out in a slow-moving water bodies. Nature even employs a host of microscopic organisms to help keep water clean. Unfortunately, if pollutants remain in the environment, clean water can easily become polluted all over again as it moves through its cycle.

Mini Investigation: Change the ShapeMaterials:

• Aluminum foil• marbles




• container to float the boats in• water to put in container

Question: What shape will keep the most weight afloat?1. Write the question on the board.2. Invite 4 students to each shape a boats from foil3. Tell them to think about what shape they should make so the shape will float while holding marbles4. Make 4 columns on the board, each labeled with the students’ name.5. Have class vote on which design they think will hold the most marbles without sinking.6. have them explain why each made the choice he/she did7. Fill a container with water8. Place aluminum foil boats in the water. Add marbles to them one at a time and see which boat

holds the most weight.

Activity Setting Up Three Water ExperimentsWhat you will need:

Case of the Disappearing Water story and the Investigation Worksheet (1 for each 3 students) 1 clear measuring cup for each group (a clear 8 ounce cup can be used if measuring cups are

not available. Simply tape one of the ruler strips onto the cup.) 4 ounce clear plastic cups (3 for each group) Celery Blue or red food coloring Salt Index cards Ruler Strips (2nd page of the Experiment Worksheet) Tape

What you will do:1. Divide youth into groups of 32. Explain to students that today they are going to set up 3 different experiments which

they will watch over the next few daysExperiment #1: The Case of the Disappearing WaterPurpose: How long does it take for ¼ cup of water to evaporate?

Experiment #2: Celery StalksPurpose: How much water will a stalk of celery absorb in a set amount

of time?

Experiment #3: Plain or Salty




Purpose: Which evaporates quicker? Plain or Salty water!

Experiment 1:1. Distribute the story of the Case of the Disappearing Water and the Investigation Worksheet to

groups2. Explain to youth the they will read the story and then complete as much of the worksheet as can

be done today (up)3. Explain that when they need the measuring cup and water they should come up and get both4. Once the experiment is set up, group may move on to experiment 2 and 3.

Experiment 2, youth will need a plastic cup, water, food coloring, celery, ruler strip, tape1. Youth will cut off the end of a celery stalk2. Youth will tape the ruler strip to the outside of the cup3. Youth will place 1 inch of water in the bottom of the cup4. Youth will mix food coloring into the water (4-5 drops of coloring)5. Youth will place the celery into the water6. Youth will predict how high the food colored water will travel in the celery in between this club

period and the next club period. Youth will indicate their prediction by placing a red mark (using a marking pen) at the place they believe the color will rise to

Experiment 3, youth will need 2 cups, one for plain water and one for salty water, salt, ruler strip, tape, index card

1. Youth will label one cup “salty” and the other “plain”2. Youth will tape ruler strip to the outside of the cup3. Youth will place 3” of water in both cups4. In the “Salty” cup, youth should stir in approximately 1 tablespoon of salt5. Youth will then predict which water will evaporate more quickly—plain or salty. Youth will record

this predication on a 3” x 5” index card6. Youth will then place the salty and plain water cups in a sunny place7. Youth will record the results each time the club meets

6 The purpose of today’s lesson is for youth to begin to consider what they can do to conserve water and yet still

In your opinion what are the most common uses of water other than drinking and bathing?

What are some

Background Information: There are many, many ways that we use our water, and that is partly why it is so important that we conserve our water. Water is our most precious resource. Water is vital to life. Humans, plants, and animals are made up of mostly water. All living things would die if it weren't for water. We use water for drinking, washing, cleaning, cooking, and growing our food as well as many, many other things. The average American uses around 150-250 gallons of water daily. Even more water is used by industries to generate electricity, manufacture things, and transport people and goods.Common household uses consume a lot of water. It may take between 30 and 40 gallons for one bath. The average toilet uses about 5 gallons of water per flush. It takes 20-40 gallons of water for one shower.


Reflect on what you’ve learned—was it a confirmation, an




maintain the life they want to maintain.

things that you do or know of that would help to conserve water?

What do you think are the biggest challenges to having enough water?

What happens to the price of water as the need (demand) exceeds the supply (amount of water that is available)

Washing machines use an average of 25 gallons per load. The kitchen sink takes roughly 20 gallons per day for preparing food and washing dishes. The bathroom sink, used for washing hands, shaving and brushing teeth, requires about 15 gallons per day. These numbers are estimated for the average household in America.

Much of our fresh water is also used outdoors for watering lawns, flower beds, and vegetable gardens, as well as washing cars and filling swimming pools. We must be careful not to pollute the water that we use outside. Many people use chemicals on their lawns and gardens and then water them with pure water. The water will wash the chemicals off of your plants and then run down a storm drain and go straight to the rivers and streams where fish make their homes. This kind of polluted water can kill fish and wildlife. We should always be mindful of whether or not we are polluting the water around us. We need to take care of our water, not abuse it.

Every town and city, whether small or big, uses water. Cities use water for fire-fighting, street cleaning, and watering public areas such as parks, grass, trees, shrubs, and flowers. Water is also used to fill public drinking fountains, including those at schools and libraries. All of the different businesses in your community also use water. Think about all the water that is used by restaurants, hospitals, laundries, dry cleaners, golf courses, hotels, car washes, beauty shops, barber shops, gas stations, and health clubs as well as all of the other businesses in town. These all add up to quite a big demand on Washington's water supply. We need to try to think about how many people need to use water and conserve our water so that there is enough to go around. (see Uses of Water Fact Sheet)Mini Investigation: Water on a PennyQuestion: How many drops of water will fit on a penny without overflowing?

1. Have youth vote yes or no and explain why each made the choice he/she did2. Dry off the penny. Fill the dropper and carefully count the drops of water as you put them on the

penny. Do not touch the dropper to the water. Do this three times.

Activity: Uses of WaterWhat you will need:

Chart paper Pens Butcher paper (30 feet) tape on wall 3 foot butcher paper squares (1 per pair) Colored pencils, colored pens

adjustment, or a new learning.

Debrief:

In what ways was this lesson active?


After doing the penny experiment do you think about the word “overflowing” in a different way? If so how is it different?,

What is your number 1 tip on how to conserve water that you are willing to commit to doing?




Painters tape Scissors Magazines, newspapers Glue sticks Miscellaneous craft supplies

What you will do:1. Ask youth to put their heads together with a partner and brainstorm a list of as many things as

they can that the water is used for. Tell them to think about how many times during the day do they use water.

2. After 5 minutes bring partners back together as a group and ask for a volunteer from the class to read the list they created, record the list on the board or chart paper

3. Ask other pairs to add to the list by sharing things were NOT written on the list. (Be sure that they have included things that cover transportation, electricity, recreation, as well as things for personal survival and comfort.

4. Divide youth into pairs again and hand out the “The Uses of Water Fact Sheet”5. Instruct students to read page 1 of the fact sheet first and then complete page 2 to help them in

designing their portion of the mural.6. Distribute to each pair the 3 foot square of butcher paper, tape, color pens, markers, scissors

and any miscellaneous craft supplies.7. Explain that the goal is to build one giant mural with the whole class. The mural will be called

“Uses of Water.”8. Each pair is to use the square of butcher paper to design their own portion of the mural.9. Students can draw, cut out magazine or newspaper pictures and use craft supplies on hand.10. Once each pair has completed their square, combine all the squares to complete one giant

mural

7 The purpose of today’s lesson is to help youth understand how water reservoirs are used to ensure that there is enough water even when there has been a dry rain year, or

What is a reservoir?

Have you ever been to a reservoir?

For what reason do you go there?

How do you think having a

Background Information: Water moves in a continuous cycle between the air, ground, and plants and animals. Most water does not naturally exist in a pure form or in a form that is safe for people to drink. That is why water must be cleaned before we drink it. Water utilities provide such treatment before water is sent through pipes to homes in communities. The demand for water varies. The availability of water also varies in different areas of the world. To meet those varying needs water utilities may store extra water in places known as reservoirs. Water is usually contained in reservoirs by a dam. Reservoirs help ensure that communities do not run out of water at any given tie regardless of the communities’ total water use.

Questions: What are some of the sources of water for a reservoir? How does water get into a reservoir?






something temporarily happens to the water source.

reservoir helps to maintain the level of water supple in your neighborhood?

What contains or holds water in a real reservoir? What kind of natural treatment does water receive in a reservoir?

Mini Investigation: EvaporationMaterial:

Eyedropper plastic container

Question: How fast does water evaporate?1. Write the question on the board2. Have students predict how long it will take for the drop of water to evaporate and explain why

each made the choice he/she did3. Write a few of the predictions on the board.4. Place 1 drop of water on a small plastic container5. Place it in the sun and check every 15-20 minutes

Activity: GroundwaterWhat you will need:

Water Reservoir Handout Groundwater Experiment Worksheet Large clear plastic container (1 per group of 3-4 students) Pebbles Sand Soil Dead leaves or dry grass Water spray bottle

What you will do:1. Divide youth into groups of 3 or 42. Give each group all the supplies and the Water Reservoir Handout3. Explain that they are going to create a groundwater reservoir using the plastic container4. Explain that they will create layers within the reservoir.

Layer 1: Small pebbles and tiny rocks Layer 2: Sand Layer 3: Soil Layer 4: Leaves

5. Once the layers have been set, carefully spray water on the four corners of the model until the soil mixture is saturated and the water has seeped through the open spaces between the pebbles.

6. Teams should record the observations7. Discuss with teams why they believe a reservoir would be a safe place to store water for a

Debrief: In what ways was this lesson meaningful?

What was the natural filtration system of the reservoir?

Does it make sense to you that if water goes through small rock and pebbles in the sunlight to help it purify?

What about this process makes sense to you?




community.

8 The purpose of today’s lesson is to help youth think about ways to conserve water by making simple adjustments to the way they live and use water.

What are the top three things that you believe you can do to conserve water?

What is your idea for getting everyone on board to conserve water?

How would this adjustment really engage many people in making small changes instead of a small number of people making drastic change?

Background Information: Will we have enough fresh water for people to live healthy lives if we continue to use water the way we do today? This is a good question. There are many ways to save water now. These don’t take money or fancy equipment. Some things you can do yourself; for others you will need some help from your family. Here are six quick water savers:

Take a quick shower. Get clean but don’t stay in for a long hot shower. When you water your lawn, do it in the morning and be sure that the water does not end up on the

driveway Check to be sure your toilet is not leaking—it could have a slow leak that you aren’t even aware of When brushing your teeth, turn the water off If you like cold water to drink, place water in the refrigerator to get cold rather than have the water

running

Mini Investigation: Water on the GlassQuestion: When you put ice in water, how does water get on the outside of the glass?Have youth explain why this happensPut three ice cubes in the glass and fill it with water. Set it on the desk and observe it for 10-15 minutes.

Activity: It All Begins With YouWhat you will need:

30 Ways to Conserve Water Handout Poster Board Colored pencils, marking pens, crayons Pencils

What you will do:1. Divide youth into pairs2. Ask each pair to think about ways they can think of to conserve water3. Give them the list of suggested ways to conserve water to review4. Explain that using either their own ideas of the tips they read to create a poster about ways that

kids can save water5. After the team has finished its poster, the team should share with the rest of the group






What do you know about water now that you did not know at the beginning of this club?

Is water an issue that you would be willing to advocate for?


Documents

keckscience.weebly.com€¦ · Web view: There are a number of different forms of water. Some are salt water—oceans, seas, bays, and gulfs and some lakes, while others are fresh