Science, Technology, and Societal Impact

Material Life Cycles means the journey a material takes from the Earth to something we use, and then what happens to it after we are done with it.

Everything we use is made from some kind of material. A material can be wood, metal, glass, paper, or plastic. These materials come from natural resources, like trees, rocks, water, and oil.

A material life cycle has steps. First, people get a resource from nature. Next, they change it into a useful material. Then, the material is made into an object we can use. After that, the object may be thrown away, reused, or recycled.

Let’s learn the main parts of a material life cycle.

1. Materials come from natural resources.

Natural resources are things people get from nature. We do not make them first. They are already part of Earth.

• Trees can be used to make paper and wood products.
• Sand can be used to make glass.
• Metal comes from rocks in the ground.
• Oil from deep in the Earth can be used to make plastic.

2. Resources are processed.

Processed means changed into a form people can use. A tree does not look like notebook paper at first. Sand does not look like a window at first. Oil does not look like a plastic bottle at first.

People use tools and machines to change raw resources into materials.

• Trees are cut and turned into pulp, then made into paper.
• Sand is heated and turned into glass.
• Metal rocks are heated so the metal can be taken out.
• Oil is changed in factories to help make plastic.

3. Materials are made into products.

A product is something people use. After a resource is processed, it can become many different things.

• Paper can become books, boxes, or tissues.
• Glass can become jars or windows.
• Metal can become cans, spoons, or bikes.
• Plastic can become toys, cups, or bottles.

4. People use the product.

This is the part we notice most. We read the book, drink from the bottle, or use the can. But the life cycle is not over yet.

5. After use, the product can have different endings.

When we are done using something, it may go in one of three directions:

• Reuse it: use it again.
• Recycle it: change it so it can become something new.
• Throw it away: put it in the trash.

Reusing is when we use the same item again without changing it very much. For example, a glass jar can hold buttons after the jelly is gone.

Recycling is when a used material is collected and changed into a new product. A paper box can become new paper. A metal can can become another metal can.

If something is thrown away, it goes to the trash. Then it may end up in a landfill, which is a place where trash is buried. When we throw things away, the life cycle often stops there.

Why do material life cycles matter?

Material life cycles matter because Earth’s resources are important. If we reuse and recycle, we can help save resources and make less trash.

• Reusing can help us use fewer new resources.
• Recycling can turn old materials into new items.
• Throwing away less can help keep places cleaner.

Some materials come from plants or animals, and some are synthetic.

Synthetic means made by people from other materials. Plastic is a common synthetic material. It is made by people in factories using materials from oil.

This means some materials start in nature and then are changed a lot before we use them.

Here are some simple life cycles to help you see the idea.

Life cycle of paper

1. A tree grows in nature.
2. People cut the tree and process the wood.
3. The wood is made into paper.
4. The paper is made into a book or box.
5. After use, the paper can be reused, recycled, or thrown away.

Life cycle of a glass jar

1. Sand is taken from Earth.
2. The sand is heated and made into glass.
3. The glass is shaped into a jar.
4. The jar holds food.
5. Later, the jar can be reused, recycled, or thrown away.

Life cycle of a plastic bottle

1. Oil is taken from deep in Earth.
2. The oil is processed in a factory.
3. The material is made into plastic.
4. The plastic is shaped into a bottle.
5. After use, the bottle can be reused, recycled, or thrown away.

Worked Example 1: Where did it start?

You have a paper bag. What natural resource did it start from?

Step 1: Think about what paper is made from.

Step 2: Paper is made from wood.

Step 3: Wood comes from trees.

Answer: The paper bag started from a tree.

Worked Example 2: What happens in the middle?

A glass window started as sand. What had to happen before it became a window?

Step 1: Sand is a natural resource.

Step 2: It must be processed.

Step 3: People heat the sand and make glass.

Step 4: Then the glass is shaped into a window.

Answer: The sand was processed into glass before it became a window.

Worked Example 3: Choose the ending

You finish a drink in a metal can. What are three possible next steps in its life cycle?

Step 1: Think about what can happen after we use a product.

Step 2: A product can be reused, recycled, or thrown away.

Answer: The metal can can be reused, recycled, or thrown away.

Worked Example 4: Put the life cycle in order

Put these in order for a plastic toy:

• toy is used
• oil is taken from Earth
• plastic is made in a factory
• toy is recycled or thrown away
• plastic is shaped into a toy

Step 1: Start with the natural resource.

Step 2: Then the resource is processed.

Step 3: Next, it becomes a product.

Step 4: Then people use it.

Step 5: Last, it is recycled or thrown away.

Answer:

1. oil is taken from Earth
2. plastic is made in a factory
3. plastic is shaped into a toy
4. toy is used
5. toy is recycled or thrown away

How can you help?

Even as a 2nd grader, you can make good choices about materials.

• Use both sides of paper.
• Reuse jars, boxes, or bags when you can.
• Put recyclable items in the recycling bin if your area collects them.
• Take care of your things so they last longer.

Remember: materials have a beginning, a middle, and an ending. They begin as natural resources, get changed into useful materials and products, and then may be reused, recycled, or thrown away.

Quick Summary

• Materials come from natural resources such as trees, sand, metal rocks, and oil.
• People process these resources to make useful materials like paper, glass, metal, and plastic.
• These materials are made into products we use every day.
• After use, products can be reused, recycled, or thrown away.
• Reusing and recycling can help save resources and reduce trash.

Citizen Science and Crowdsourced Data means that everyday people help scientists collect information and make discoveries.

Scientists cannot be everywhere at once. There are too many birds to count, too many stars to watch, and too many places to check air quality every day. When many people help, scientists can learn much more.

This teamwork is called citizen science. The information people send in is called data. When a large group of people shares data, it is called crowdsourced data.

Citizen science shows that science is not only for people in labs. Families, students, neighbors, and communities can all help answer science questions.

Why is citizen science important?

• It helps collect more information. One scientist may only study a small area, but thousands of helpers can study many places.
• It helps track change over time. People can report the same kind of data again and again, like birds seen each spring.
• It helps communities. Local people can learn about their own air, water, plants, and animals.
• It helps solve problems. Good data can help leaders make decisions about health, safety, and the environment.

How does citizen science work?

1. Scientists ask a question.
2. People collect observations or measurements.
3. People send the data to a shared project.
4. Scientists study the data to look for patterns.
5. The results can help people understand the world and make choices.

An observation is something you notice using your senses or simple tools. For example, you might observe a red bird at your feeder or notice that the air smells smoky.

A pattern is something that happens in a repeated way. If many people report seeing robins in spring, that can show a seasonal pattern.

Example 1: Tracking bird migration

Birds move from one place to another during different seasons. This is called migration. Scientists want to know when birds arrive, where they stop, and how their paths may change.

People in many towns can watch for birds and report what they see. If one person reports 3 geese and another person reports 5 geese, the total number reported is:

$$3 + 5 = 8$$

That may seem small, but if hundreds or thousands of people report birds, scientists get a much bigger picture. They can see where birds are traveling and if bird numbers are changing.

Worked Example 1

Four students report the number of robins they see in one morning:

• Student A: 2 robins
• Student B: 4 robins
• Student C: 1 robin
• Student D: 3 robins

How many robins were reported altogether?

Add the numbers:

$$2 + 4 + 1 + 3 = 10$$

Answer: The students reported 10 robins altogether.

This shows how a group can collect more data than one person alone.

Example 2: Measuring local air quality

Air quality tells us how clean or dirty the air is. Clean air is healthier to breathe. Some citizen science projects ask people to use simple tools or apps to report smoke, dust, or pollution.

If people in many neighborhoods collect air data, scientists can learn which places have cleaner air and which places may need help. This can also help leaders decide where to make changes, like planting more trees or reducing pollution.

Worked Example 2

A class checks the air in 3 places near school. They give each place a simple pollution score:

• Park: 1
• Busy road: 5
• Playground: 2

Which place had the highest pollution score?

Compare the numbers: 1, 5, and 2.

The greatest number is 5.

Answer: The busy road had the highest pollution score.

This kind of data can help people understand their community and think about ways to make it healthier.

Example 3: Looking for unusual things in space

Scientists study stars, planets, and other objects in space. But there are so many pictures and signals from space that scientists sometimes need help looking through them.

Volunteers can help spot things that seem different, such as a strange light pattern or an object moving in a new way. These unusual findings are sometimes called anomalies, which means something that does not match the usual pattern.

When many people check images carefully, they may notice something important that a computer or even a scientist might miss at first.

Worked Example 3

A space project asks 6 volunteers to review pictures. Two volunteers each find 1 unusual picture, and one volunteer finds 2 unusual pictures. The other volunteers find none.

How many unusual pictures were found in all?

Add the findings:

$$1 + 1 + 2 = 4$$

Answer: The volunteers found 4 unusual pictures in all.

This shows that each helper can make a useful contribution.

What makes crowdsourced data useful?

• Many helpers: More people can cover more places.
• Repeated reports: Data collected over many days, months, or years can show change.
• Different locations: People in cities, towns, forests, and farms can all share what they observe.
• Quick sharing: Technology like phones, tablets, and computers helps people send data fast.

Why do scientists need careful data?

Data is most helpful when it is collected carefully. People should follow directions, be honest, and report what they really observe.

For example, if a student guesses instead of counting, the data may not be correct. If many people make mistakes, the results can be harder to trust.

Good citizen scientists try to:

• look closely,
• count carefully,
• write down the right place and time,
• use tools correctly,
• and send truthful information.

How does this connect to technology and society?

Technology helps citizen science happen. Apps, websites, cameras, and simple sensors make it easier for people to collect and share data.

When scientists and communities learn from this data, it can affect society in important ways. It can help protect animals, improve public health, and teach people more about the environment.

For example, if crowdsourced data shows poor air quality in many neighborhoods, leaders may decide to make rules that reduce pollution. If bird data shows fewer birds in an area, people may work to protect habitats.

This means science and technology can shape decisions in communities. Public participation gives more people a voice in understanding problems and helping find solutions.

Things to remember about citizen science

• Anyone can help with science by making careful observations.
• Citizen science is teamwork between the public and scientists.
• Crowdsourced data comes from many people sharing information.
• This data can help track birds, air quality, weather, plants, and even objects in space.
• Careful, honest data helps scientists make better conclusions.

Quick Check

Suppose 3 neighbors report birds in their yards:

• Neighbor 1: 6 birds
• Neighbor 2: 2 birds
• Neighbor 3: 7 birds

How many birds were reported in all?

$$6 + 2 + 7 = 15$$

Answer: There were 15 birds reported in all.

By putting their data together, the neighbors learned more than any one person could alone.

Summary

Citizen science is when ordinary people help scientists by collecting observations and sharing data. Crowdsourced data is powerful because many people can work together across many places and times.

This helps scientists study bird migration, air quality, and unusual events in space. With careful observations and the help of technology, communities can support science and help make the world healthier and smarter.

Diversity and Equity in STEM

STEM stands for science, technology, engineering, and math. These are the subjects people use to ask questions, solve problems, invent tools, and make life better.

Diversity means people are different in many ways. They may have different backgrounds, cultures, languages, abilities, ideas, and life experiences.

Equity means being fair. It means making sure people get the support and chances they need so they can learn, participate, and succeed.

In STEM, diversity and equity are important because big problems need many different ideas. When people with different experiences work together, they can notice different problems and think of better solutions.

For a long time, not everyone had the same chance to join STEM. Some people were left out because of unfair rules, unfair treatment, or because schools and jobs were not welcoming to them. Even when they did amazing work, they were not always given credit.

This lesson will help you learn why diversity and equity matter in STEM, how underrepresented groups have helped science and technology, and how fairness helps everyone.

What does “underrepresented” mean?

Underrepresented means a group has fewer people in a place than we might expect. In STEM, some groups have often had fewer chances to learn, work, lead, or be noticed.

These groups can include:

• women and girls
• people from different racial and cultural backgrounds
• people with disabilities
• people from families with less money
• people who live in places with fewer schools or fewer tools

Being underrepresented does not mean people in these groups are less smart or less creative. It often means they faced barriers that made it harder to join or be recognized.

What are barriers?

Barriers are things that get in the way. In STEM, barriers can stop people from learning, participating, or being treated fairly.

Some barriers from the past and present include:

• schools that did not allow everyone to attend
• people being told, “STEM is not for you”
• not having books, computers, labs, or internet access
• buildings, tools, or lessons that were not designed for everyone
• people doing great work but not getting credit for it

These barriers are called structural barriers when they are built into systems like schools, workplaces, and rules. Structural barriers can affect many people, not just one person.

Why does diversity make STEM stronger?

Science and technology are about solving problems. Different people notice different needs.

For example, one inventor may notice a problem in a city, while another may notice a problem in a farm community. One scientist may think about clean drinking water, while another thinks about making hospitals easier to use. Together, they can build smarter solutions.

Diverse teams can help because they:

• bring many ideas to one problem
• ask new questions others may miss
• design tools for more people
• make science fairer and more useful

Why does equity matter?

Equity means giving people what they need to have a fair chance. Fair does not always mean everyone gets the exact same thing.

For example, if one student can see small print clearly and another cannot, fairness may mean giving one student larger print. Both students are important. They just need different support.

In STEM, equity can look like:

• providing ramps, captions, or tools for different abilities
• making sure all students can use science materials
• offering books and lessons that show many kinds of scientists
• encouraging every student to ask questions and share ideas

Important contributions from underrepresented groups in STEM

Many people from underrepresented groups have made important discoveries and inventions. Their work has helped medicine, space travel, farming, communication, and daily life.

Katherine Johnson was a mathematician who helped calculate paths for space missions. Her math helped astronauts travel safely. She was a Black woman working at a time when unfair treatment made her job harder, but her work was very important.

George Washington Carver was a scientist who studied plants and farming. He taught ways to help soil stay healthy and helped farmers grow crops in better ways.

Ellen Ochoa is an engineer and astronaut. She became the first Latina woman in space. Her work showed that people from many backgrounds belong in science and space exploration.

Temple Grandin is a scientist and inventor who has autism. She designed systems to improve how animals are treated. Her unique way of thinking helped her see problems in new ways.

These people are only a few examples. STEM has been shaped by many people whose stories were not always taught in books.

Worked Example 1: Different ideas help solve a problem

A class wants to design a school garden. One student knows a lot about plants. Another student knows how to save water. Another student uses a wheelchair and notices that some paths are too narrow.

Question: Why is this team stronger because it includes different people?

Answer: Each student notices something important. One helps plants grow, one helps protect water, and one helps make the garden easier for everyone to use. Because the team has different experiences and ideas, the garden plan can be better for more people.

Worked Example 2: Spotting a barrier

A science club meets after school. Some students want to join, but they cannot get home safely that late. Other students cannot join because the club room is upstairs and there is no elevator.

Question: What barriers are stopping students from joining?

Answer: One barrier is transportation after school. Another barrier is that the room is not easy for everyone to reach. These barriers are unfair because they keep some students out.

How could the club be more equitable? The club could meet earlier, help families with transportation plans, or move to a room everyone can enter.

Worked Example 3: Fair is not always the same

Three students are doing a science activity. One student needs instructions read aloud. One student needs bigger pictures. One student can use the regular paper.

Question: Is it fair if the teacher gives different supports to different students?

Answer: Yes. Equity means students get the support they need. The goal is for everyone to have a fair chance to learn and participate.

Worked Example 4: Giving credit where it is due

A team of scientists makes an important discovery. One scientist does careful testing, but only the team leader is thanked in the newspaper.

Question: Why is this a problem?

Answer: It is a problem because everyone who helped should be recognized fairly. When people do not get credit, others may not learn about their work, and it can make STEM less fair.

How diversity and equity help solve global problems

The world faces big problems like pollution, disease, hunger, and natural disasters. No one person can solve these problems alone.

When many kinds of people work in STEM, they can think about problems from different angles. A scientist in one country may understand local weather patterns. An engineer in another place may design better tools. A doctor may notice what patients need. A computer expert may help share information quickly.

This is why diverse STEM teams are powerful. They help create solutions that work for more people around the world.

What can students do?

You can help make STEM more fair and welcoming. Even as a 4th grader, your actions matter.

• Listen to other people’s ideas.
• Invite classmates to join group work.
• Do not say some subjects are only for certain people.
• Learn about scientists from many backgrounds.
• Speak up when something seems unfair.
• Believe that everyone can grow and learn.

Key ideas to remember

• Diversity means people bring different backgrounds, ideas, and experiences.
• Equity means being fair and giving people the support they need.
• Some groups have been underrepresented in STEM because of unfair barriers.
• People from underrepresented groups have made important contributions to science and technology.
• STEM is stronger when everyone has a chance to participate and be respected.

Brief Summary

Diversity and equity in STEM matter because science and technology work best when many different people can take part. In the past, unfair barriers kept some groups from joining or getting credit, even though they made important contributions. When STEM is fair and welcoming, people can share more ideas, solve bigger problems, and create solutions that help everyone.