Chapter: 07. Forms Of Matter Solids, Liquids And Gases
Unjumble the given letters to find the correct words.
List any two examples of each of the following.
Table, Chair (Other valid answers: Tree, Mobile phone, Lego blocks, Ice, Pakora, Umbrella, Pens, Pencils, Sharpener, Balloon) Milk, Water (Other valid answers: Juice, Rain, Kerosene, Olive oil, Lemonade, Ink) Water vapour, Air (Other valid answers: Steam, Oxygen, Carbon dioxide) Quick Check: Cross (X) the odd one out.
Bag, Carbon dioxide, Steam Bag (Solid, while Carbon dioxide and Steam are gases) Scissors (Solid, while Juice and Ink are liquids) Juicer (Solid, while Steam and Oxygen are gases) Bottle, Water vapour, Tank Water vapour (Gas, while Bottle and Tank are solids) Run-Through: I. Very Short Answer Questions
A. Tick (✓) the correct answer.
Everything around us is known as Which among the following is a gas? Which of the following is an example of matter? Which of the following changes into all three forms? B. Identify the forms of matter-Solid (S), Liquid (L) or Gas (G). One is done for you.
1. Ice
* S
2. Tree
* S
3. Glass
* S
4. Kerosene
* L
5. Oxygen
* G
6. Eraser
* S
7. Olive oil
* L
8. Lemonade
* L
9. Bus
* S
C. Put tick (✓) or cross (X). One is done for you.
D. Complete the concept map.
Examples: Ice, Snow, Glacier Examples: Water, Rain, Dew Examples: Steam, Water Vapour, Fog II. Short Answer Questions
Define matter. Name the three different forms of matter. Matter is anything that has mass and occupies space. The three different forms of matter are solids, liquids, and gases. Write any one difference between solids, liquids and gases. Solids have a fixed shape and size, while liquids do not have a fixed shape but take the shape of their container, and gases do not have a fixed shape or size and fill the entire container. (Other valid differences can be based on flow or fixed space.) III. Long Answer Questions
Explain the three different forms of matter. Solids: Solids have a definite shape and a definite volume (size). Their particles are closely packed and vibrate in fixed positions, which is why they cannot flow. Examples include a chair, a book, or an ice cube. Liquids: Liquids have a definite volume but no definite shape. They take the shape of the container they are in. Their particles are close together but can move past one another, allowing liquids to flow easily. Examples include water, juice, or milk. Gases: Gases have neither a definite shape nor a definite volume. They expand to fill the entire volume of any container they are in. Their particles are very far apart and move freely and rapidly, which is why gases flow easily and are often invisible. Examples include air, oxygen, or steam (water vapour). With the help of an activity, show that a liquid can flow and takes the shape of its container. Aim: To demonstrate that liquids flow and adapt to the shape of their container. Materials: A bottle of water, a glass, a bowl, and a shallow plate. Pour the water from the bottle into the glass. Observe that the water takes the cylindrical shape of the glass. Next, carefully pour the water from the glass into the bowl. Observe that the water now takes the rounded shape of the bowl. Finally, pour the water from the bowl onto the shallow plate. The water will spread out and take the flat, wide shape of the plate. Observation: In each step, the water (a liquid) flowed easily from one container to another and always changed its shape to match the container it was in. This shows that liquids can flow and do not have a fixed shape but take the shape of theirrier they are present in. IV. Challenge
Manvi took a stick and tied two inflated balloons of equal size on two sides of the stick as shown in the picture. She then pricked a balloon and the stick tilted to one side. What does this show? This shows that air, even though it’s a gas and invisible, has mass and occupies space. When one balloon was pricked, the air escaped, making that side lighter, causing the stick to tilt towards the side with the unpricked, inflated balloon (which still contained air and thus had more mass). This demonstrates that air is a form of matter. Mihika lighted incense sticks in one corner of the drawing room. It made the whole room smell good. Why? When incense sticks burn, they release tiny particles of scent into the air. These scent particles, which are in the gaseous form, mix with the air and spread out through the entire room. Gases naturally spread out to fill all available space, which is why the smell diffused from one corner to fill the whole drawing room. V. Enrichment
A. Research/Activity
When naphthalene balls are kept in an airy place, their size will gradually decrease over time, and they will eventually disappear without melting. This phenomenon is called sublimation. Sublimation is the process where a solid changes directly into a gas without first becoming a liquid. The naphthalene molecules escape directly from the solid state into the air as a gas, which is why the size of the balls changes and they seem to disappear. Science Quest
Glaciers: Glaciers are large, perennial accumulations of crystalline ice, snow, rock, sediment, and liquid water that originate on land and move downslope under the influence of their own weight and gravity. They are essentially slow-moving rivers of ice. Why glaciers are melting so fast: Glaciers are melting rapidly primarily due to global warming, which is caused by the increase in greenhouse gases in the Earth’s atmosphere. These gases trap heat, leading to a rise in global temperatures, which in turn causes ice to melt at an accelerated rate. Outcome: The rapid melting of glaciers contributes significantly to rising sea levels, which can lead to coastal flooding, displacement of populations, and destruction of coastal ecosystems. It also impacts freshwater supplies for communities that rely on glacial meltwater and can alter ocean currents and climate patterns. Specific term: The phenomenon explaining the rapid melting of glaciers and ice sheets due to global temperature rise is often referred to as climate change, specifically focusing on glacial retreat and ice sheet mass loss. Acrostic poem (Examples, students should create their own)
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