Properties of substances booklet
Properties of substances booklet
- Unit 1: The human body
- Unit 2: Materials
- Unit 3: Rocks, the rock cycle and soil
- Unit 4: Food chains and food webs
- Unit 5: Forces and electricity
- Unit 6: Light and the Solar system
🌟 This Topic is About...
- 🌡️ I will learn that the temperature at which a substance changes state is a property of that substance.
- 💧 I will find out the difference between boiling and evaporation.
- 🌡️ I will learn how to measure temperature correctly.
- 📊 I will collect and record measurements in tables and graphs.
- 🧪 I will learn how to work safely in practical investigations.
- 📈 I will draw graphs and use them to make conclusions.
- ⚖️ I will plan fair tests and choose the right materials and equipment.
- 🚨 I will identify risks and plan how to work safely.
- 💨 I will explore the properties of gases.
- 🔬 I will use scientific knowledge to make and test predictions.
Get ready to investigate heat, gases, and scientific testing! 🌡️🔍
🌟 Key Words
- boiling point
- melting point
- property
📖 Tap to Learn the Meanings!
- 🔥 boiling point: The temperature when a liquid turns into a gas, like water boiling into steam.
- ❄️ melting point: The temperature when a solid changes into a liquid, like ice melting into water.
- ⚗️ property: A special feature of a substance that helps describe what it’s like or how it behaves.
You’ve mastered the key science words about changing states! 🌡️✨
🔥 Change of State
When substances are heated or cooled enough, they can change from one state to another. For example, when we heat ice, it melts and becomes liquid water. Ice melts at a temperature of 0 °C. The temperature at which a solid becomes a liquid is called the melting point. Gold is also a solid, and its melting point is 1064 °C.
💡 Understanding Properties
Melting point is a property of a substance. A property is something that helps us tell one substance apart from another. Each substance has its own unique melting point, which helps us identify it.
🔥 Boiling Point and Energy
Boiling point is another important property of a substance. It is the temperature at which particles throughout a liquid gain enough energy to change into a gas. Each substance boils at a specific temperature — for example, pure water boils at 100 °C, vinegar boils at 118 °C, and liquid gold boils at 2856 °C.
💨 Boiling and Evaporation
Liquids can change into gases when they boil or evaporate. These two processes both involve heating, but they happen in different ways.
When a liquid boils, all of the particles throughout the liquid gain enough energy to become gas particles. In evaporation, only the particles on the surface of the liquid change into gas. Most liquids boil only when they are heated to their boiling point, but evaporation can happen at any temperature.
🔍 Think Like a Scientist: Measure and Compare Melting Points
🎯 Aim: To measure and compare the melting points of three different solid substances.
🧰 You will need: Three different solids, three pans, a hotplate, a thermometer, and a stopwatch or digital watch.
🧑🏫 Activity Type: This is a teacher demonstration.
⚠️ Safety First:
- Do not touch the hot plate or pan — it can burn you!
🧪 Method:
- Place a solid in a pan.
- Heat the solid substance until it melts. Remove the pan from the hot plate as soon as the substance melts.
- Measure the temperature of the melted substance. Record the reading in a table.
- Repeat steps 1–3 with the other two solids.
❓ Questions:
- a) the highest melting point?
- b) the lowest melting point?
👀 Tap to See Possible Answers
- 1a: The substance that melted at the highest temperature had the highest melting point. 🔥
- 1b: The substance that melted first had the lowest melting point. ❄️
- 2: The bar chart should show temperatures for each substance. 📊
- 3: Different substances have different melting points — it’s a property of each material. 🧪
- 4: The melting point would not change, because it depends on the substance, not the amount. ⚖️
- 5: Boiling needs more energy than melting, so it always happens at a higher temperature. 🌡️
Fantastic work investigating melting points like a real scientist! 🧠👏
🔍 Let’s Investigate: Comparing Boiling Points
🎯 Aim: To plan a fair test that compares the boiling points of different substances.
👩🔬 Work in groups to design your test carefully so that it is fair and safe. You will need to think about what to change, what to keep the same, and what to measure.
❓ Investigation Questions:
- In your test, which variables will you:
• change?
• keep the same?
• measure? - What materials and equipment will you need?
- What will you do to compare the boiling points of the different substances?
- Are there any dangers or risks in your investigation? How will you work safely?
- How will you record and present your results?
🧰 You could test substances such as: water, vinegar, orange juice, milk, honey, and cooking oil.
🛡️ Safety Tips:
- Handle hot liquids carefully — use tongs or heatproof gloves. 🧤
- Work with an adult when using heat sources. 👩🏫
- Keep all electrical equipment away from water. ⚡💧
🗂️ Reflect and Discuss:
- How well can you identify different variables in a fair test? 🔄
- Can you choose the best materials and equipment for your investigation? ⚗️
- Can you plan how to record and present your results clearly? 📊
🌟 Tap to See Hints
- Change: The type of liquid being tested (water, milk, etc.).
- Keep the same: The volume of liquid and the heat source.
- Measure: The temperature when the liquid starts to boil. 🌡️
- Safety: Be careful with boiling liquids and hot surfaces. 🔥
- Results: Record boiling points in a table and compare them. 📋
Brilliant thinking, scientist! Keep testing safely and fairly! 👏🧠
💨 Properties of Gases
Air is a mixture of gases, and gas is one of the states of matter. All matter has certain properties — it takes up space and has mass. This means that even though we can’t always see or feel air, it is still there, surrounding us and filling every empty space.
🔍 Let’s Investigate: The Properties of Gases
🤔 Question: How can we show that gases take up space and have mass?
🧰 You will need: Two balloons of the same size, two rulers, string, a heavy book, twist ties, scissors, sticky tape, and safety goggles.
🛡️ Safety First:
- Take care when handling heavy books — they can fall or hurt your hands. 📚⚠️
- Wear safety goggles when inflating balloons. 🥽
🧪 Method:
- Blow up two balloons to the same size and tie them off tightly with twist ties. 🎈
- Measure and cut three pieces of string, each 15 cm long. ✂️
- Use two strings to tie the balloons onto one of the rulers. Keep them the same distance from the ends of the ruler. 📏
- Put a second ruler near the edge of the table and hold it down with a heavy book. The other end should stick out over the edge. 📚
- Use the third string to hang the ruler with balloons from the second ruler so it can balance. 🔗
- Carefully adjust the setup so the balloons are balanced. Tape them in place so they don’t move. 🧷
- a) Predict what will happen if you loosen the twist tie on one balloon.
b) Loosen it and observe what happens. Was your prediction correct?
c) Make a drawing of what you saw. ✏️
❓ Follow-up Questions:
- How does this investigation show that gases take up space?
- How does this investigation show that gases have mass?
- How did you work safely in the investigation?
🌟 Tap to See Answers
- 1: The balloon with air pushes against the other balloon — air takes up space. 🌬️
- 2: When one balloon is deflated, the balance tips — air has mass. ⚖️
- 3: We worked safely by using goggles, tying balloons securely, and handling books carefully. 🧤
Excellent work showing that even invisible gases have properties! 💡👏