Gases
🌟 This Topic is About...
- 💨 I will learn that some substances are gases.
- 🔬 I will explore the particle model for solids, liquids, and gases.
- 🌍 I will find out about the different gases in the air.
- 🏭 I will discover how some substances in the air cause pollution.
- 🤔 I will make a prediction about air pollution and test if I am right.
- 📊 I will record my results using drawings, tables, and dot plots.
Let’s explore the air around us and become air detectives! 🌬️🔍
🌟 Key Words
- atmosphere
- compressed
- invisible
- layer
- pollute
- pollution
- properties
- structure
📖 Tap to Learn the Meanings!
- 🌍 atmosphere: The layer of air that surrounds the Earth.
- 💨 compressed: When something is squeezed into a smaller space.
- 👀 invisible: Something you cannot see with your eyes.
- 📚 layer: One part of something that lies on top of or under another.
- 🚯 pollute: To make the air, water, or land dirty or harmful.
- 🌫️ pollution: The presence of harmful or dirty substances in the environment.
- ⚗️ properties: The special features that describe how something looks, feels, or behaves.
- 🏗️ structure: The way parts of something are arranged or built together.
Now you know the important science words for this topic! 🌟✨
💨 Gases Around Us
Gases are all around us — the air we breathe is a mixture of gases. Gases are also found in fizzy drinks and inside bicycle and car tyres.
We don’t always realize that gases are there because we can’t see most of them. These gases are invisible. We also can’t smell or taste many gases around us.
🧪 Think like a Scientist 1 — Make a Gas
🧰 You will need: Vinegar, bicarbonate of soda, a jar with a wide mouth, and a spoon.
When we mix some materials, they react to make a gas. You are going to make carbon dioxide gas!
- Pour some vinegar into the jar.
- Put a teaspoon of bicarbonate of soda into the jar.
- Observe what happens. 👀
❓ Questions
- What state of matter is:
- Vinegar?
- Bicarbonate of soda?
- The new substance that forms?
-
- Draw a picture to show what happened when the bicarbonate of soda mixed with the vinegar. Label the liquid and the gas. 🎨
- Write a sentence to describe what happened when you mixed them. ✍️
💭 How am I doing?
- Did I follow the instructions carefully?
- Did I observe a gas and draw my observations?
- Could I write a sentence to describe what I saw?
Point to a face to show how you feel about your work: 😀 😐 ☹️
💡 The Particle Model of Matter
In Stage 4, you learnt that solids, liquids, and gases are all made up of particles that move. The particle model of matter describes the structure of solids, liquids, and gases and explains their properties.
🧊 Solids
In solids, the particles are very close together, leaving only small spaces between them. The particles are arranged in a regular pattern and cannot move freely, though they can vibrate slightly. Because the particles are held tightly together, solids have a fixed shape and volume and cannot be easily compressed.
💧 Liquids
In liquids, the particles are close together but not as tightly packed as in solids. They have small spaces between them and are not arranged in a fixed pattern. The particles can move and slide past each other, which allows liquids like water to flow and take the shape of their container.
🌬️ Gases and the Particle Model
Some substances are gases. In gases, the particles are very far apart and move freely in all directions. There are large spaces between them, and they move quickly because they are not held together strongly. This is why gases such as air have no fixed shape or volume—they spread to fill the space available.
🔍 Let’s Investigate! — Describe Solids, Liquids and Gases
🤔 Question: How can we describe and compare solids, liquids and gases using the particle model?
🧰 Equipment: Pencil ✏️, science notebook 📘, ruler 📏, and coloured pencils 🎨 for drawing particle models.
📝 Task: Draw, label, and explain how particles behave in each state of matter.
🧠 Activity Steps:
- Draw the particle model for each state of matter of water:
- Water (liquid) 💧
- Water vapour (gas) 🌬️
- Ice (solid) 🧊
- Answer the following questions about particle arrangement:
- In which state are the particles very close together?
- In which state are the particles very far apart?
- In which state do the particles move fast in all directions?
- In which state are the particles close together but not in a fixed pattern?
- Explain what the particle model shows about the structure of solids, liquids, and gases. 💭
- Explain why we can squash a gas but cannot compress or squash a solid. 🔍
🌟 Tap to See Example Answers
- 1: In solids, particles are tightly packed. In liquids, they slide past each other. In gases, they move freely.
- 2:
- a) Solids
- b) Gases
- c) Gases
- d) Liquids
- 3: The particle model shows that matter is made of moving particles that are arranged differently in each state.
- 4: Gases can be squashed because there is space between particles, but solids cannot because their particles are tightly packed.
Excellent thinking! You’ve described the states of matter clearly. 🌟👏
🌍 Air and Its Composition
Air is a mixture of different gases. A gas called nitrogen makes up about four-fifths of the air. Air also contains a gas called oxygen, which we need to live. When we breathe in, we take in oxygen. When we breathe out, we release carbon dioxide, which is also found in the air. Air also contains a gas called water vapour.
☁️ The Atmosphere Around Earth
The layer of air that surrounds the Earth is called the atmosphere. The atmosphere protects life on Earth and helps to keep the planet warm. There are also many other gases that are not found in large amounts in the air, such as hydrogen and helium.
💨 Air Pollution
It is very important for us to have clean air to breathe. In many parts of the world, the air is not clean. People release smoke, dust, and gases from factories, power stations, cars, trucks, and aeroplanes into the air. These substances make the air dirty and harmful to living things. We say that they cause air pollution.
🏠 Air Pollution Indoors
Air pollution is not only found outside. Homes, schools, and buildings can also have air pollution. Many everyday activities can pollute the air. Smoke from cigarettes and cooking, and fumes from spray cans or paints, all add to indoor air pollution.
💔 Effects of Air Pollution
Air pollution can make us cough, feel dizzy, and cause headaches. Breathing polluted air can also lead to serious health problems. The smoke from cigarettes, for example, can damage our lungs and cause long-term breathing diseases.
🔍 Think Like a Scientist 3 — Measure Air Pollution
🤔 Question: Which places have the most air pollution, and why?
🧰 You will need: five pieces of white or clear plastic, petroleum jelly, a marker pen, a ruler, tape, and a box 📦
📝 Method:
- On one side of each piece of plastic, use a marker pen to mark an area that is 4 cm long and 2 cm wide.
- Put the pieces of plastic in five different places, such as your classroom, schoolyard, garage, park, lamppost, or kitchen.
- Cover the marked area of each piece of plastic with a thin layer of petroleum jelly. Then tape the pieces in place.
- Predict which place will have the most polluted air and explain why. 💭
- Leave the pieces for three days. Then carefully put them in a box and bring them back to school. Don’t touch the jelly!
- Observe the amount of air pollution collected on each marked area. 👀
- Draw what you see on each piece of plastic to show how much pollution there is.
- Number your drawings from 1 (least pollution) to 5 (most pollution).
- Record your results in a table like this one:
| Piece of plastic | Place it was put | Amount of pollution observed |
|---|---|---|
| A | ||
| B | ||
| C | ||
| D | ||
| E |
📊 Continued:
- Draw a dot plot of your results to show how much pollution was found at each place.
- Was your prediction correct? Which place had the most air pollution?
- Which place had the least air pollution? Suggest a reason for this. 🌿
🌟 Tap to See Example Answers
- Prediction: The garage or near the road will have the most pollution because of car exhausts.
- Observation: The pieces near traffic had more dust and black spots.
- Conclusion: Areas with more vehicles or smoke have higher air pollution.
Excellent investigation! You’ve learned how to measure air pollution scientifically. 🌍👏
🔍 Think Like a Scientist 3 — Measure Air Pollution (Continued)
🧮 Continue your investigation:
- Draw a dot plot of your results to show how much pollution was found at each place. 📊
- Was your prediction correct? Which place had the most air pollution? 🤔
- Which place had the least air pollution? Suggest a reason for this. 🌿
Use your results to explain what you discovered about air pollution in different places.
🌟 Tap to See Example Answers
- Dot plot: Each piece of plastic is shown on the x-axis, with dots representing how much pollution was found.
- Prediction: The garage or roadside had the most pollution because of car fumes. 🚗
- Least pollution: The park had the least pollution because there were fewer vehicles and more trees. 🌳
Brilliant work completing your investigation — you're becoming a real scientist! 👏🌍