Matter (Substance)

1. Aim: To observe the change in the state of wax from solid to liquid when heated and back to solid when cooled.

2. Requirements: wax pieces, bowl, candle or spirit lamp, and cold water.

3. Procedure

Heating Process:

• Place wax pieces in a bowl.
• Heat the bowl using a candle or spirit lamp.

Observation (A):

• The wax melts, changing from solid to liquid.
• Initial State: Solid
• After Heating: Liquid

Cooling Process: Place the bowl with liquid wax in cold water.

Observation (B): The wax cools down and returns to its solid state.

4. Conclusion: This experiment demonstrates the change of state of a substance due to temperature variations-melting when heated and solidifying when cooled.

 Change of state of wax

1. Aim: To observe how solid materials like candy, sugar, or coal break down into smaller particles when pounded.

2. Requirements: small pieces of candy, sugar, coal, a mortar and a pestle.

3. Procedure

• Place small pieces of candy, sugar, or coal in a mortar. Use a pestle to pound the pieces and apply pressure repeatedly.
• Observe the changes in the material as it breaks into smaller pieces or turns into powder.

4. Observation: The candy sugar or coal breaks down into smaller particles, forming a powder.

5. Conclusion: When solid materials like candy, sugar, or coal are pounded, they break down into smaller particles or powder, demonstrating that large solids can be broken into finer pieces through physical force.

Pounding pieces of coal

1. Aim: To understand that the properties of matter remain the same, even when divided into smaller parts or spread out.

2. Requirements: a piece of chalk, a handkerchief, an ink drop, and a perfume bottle.

3. Procedure

• Chalk experiment: Take a piece of chalk and keep dividing it into smaller pieces. Observe the colour and properties of the smaller pieces.
• Ink experiment: Place a drop of ink on a handkerchief and wipe it. Observe the effect of ink on the cloth.
• Perfume experiment: Open the lid of a perfume bottle in a room. Observe how the fragrance spreads throughout the room.

4. Conclusion

• Chalk: Even when divided, the smaller pieces retain the same white colour and properties.
• Ink: The blue colour of the ink remains on the cloth, showing that the matter retains its properties even when absorbed.
• Perfume: The fragrance spreads through the air, showing that the matter in gases retains its properties even when spread out.

1. Aim: To understand that matter has mass and volume and can be measured.

2. Requirements: glass of water, small stone, balance (weighing scale), big and small stones.

3. Procedure

• Activity 1: Dropping a Stone in Water: Fill a glass of water to the brim. Carefully drop a small stone into the water. Observe what happens to the water.
• Activity 2: Comparing Mass of Stones: Place a small stone on one pan of the balance and a big stone on the other. Observe which pan goes down and note why.

4. Conclusion

• From Activity 1: When the stone is dropped, some water spills out. This shows that the stone occupies space (volume).
• From Activity 2: The pan with the bigger stone goes down, showing more mass than the smaller one.

These activities show that matter has two important properties: mass and volume.

• Mass: Matter has weight, which can be measured using a balance.
• Volume: Matter occupies space, as seen from the displacement of water by the stone.

1. Concept of Substance (Matter): Matter is made of one or more components known as substances. A substance is a matter that has definite properties and composition. Every pure compound and element is a substance. For example, Iron, Sodium chloride, etc.

2. Properties of Substance

• A substance is a matter that cannot be separated into any other type of matter by some physical means.
• The substance must be composed of atoms and molecules. Matter is made of one or more components known as substances.
• The substance must have a particular weight, mass, and volume.
• When a substance changes from one state to another, the process is called a change of state of the substance. The state of a substance changes if it is heated or cooled. Every substance in our surroundings is found in either the solid, liquid, or gaseous state.

For example, a single material can be used to create various objects:

• Cotton: It is used to make cloth, sarees, handkerchiefs, quilts, mattresses, and pillows.
• Iron: It is utilised for the construction of steel bars, griddles (tawa), automobile parts, electric poles, tables, cupboards, and more.
• Aluminium: Commonly found in kitchen utensils and electrical cables.

Different objects

3. Types of Substance

i. Pure Substance: A substance that has only one component and nothing else in it is called a pure substance. A pure substance is anything composed of a single type of material. In other words, it is free of contaminants.

Examples,

1. Tin
2. Sulphur
3. Diamond
4. Sugar
5. Water

ii. Impure substance: The impure substance is any substance of interest containing some (small or large) unwanted material. It contains a random number of constituent particles; that makes it nothing but a mixture that does not contain a fixed amount of matter.

Examples,

1. Salt mixed in water
2. Chocolate chips dipped in cookies
3. Fruit salad
4. Muddy  water
5. Milk and cereals
6. Vegetable soup
7. Rocks
8. Sand mixed in water
9. Sandwich
10. Milkshake

Matter is made up of very small particles. These small particles are called atoms. These particles cannot be seen by the naked eye as they are too small in size. Atoms can be observed under an electron microscope. These tiny particles combine to make all the objects and materials we use every day. In the 19th century, the scientist J. Willard Gibbs showed that the characteristic properties of a substance depend on its physical state and the arrangement of particles in it.

Example of Atoms in Matter:

• A drop of water is made up of billions of water atoms.
• A piece of chalk is made up of many tiny chalk atoms

Chemical properties of matter tell us how a substance changes when it interacts with other substances. These properties describe how matter reacts and forms new substances. When a chemical change happens, the matter changes into something new. The atoms in a substance rearrange themselves, and a new substance is formed. For example:

• When wood burns, it turns into ash and smoke.
• When iron is exposed to air and water, it forms rust.

Examples of Chemical Properties:

• Flammability: This describes if a substance can burn. For example, wood is flammable because it can catch fire.
• Reactivity: This tells us how a substance reacts when mixed with others. For example, if you mix vinegar with baking soda, they react to create bubbles.
• Rusting: Some metals, like iron, will form rust when they come in contact with water and air.
• Acidity and Basicity: Some substances are acidic (like lemon juice), while others are basic (like soap). Acids and bases can react with each other to form new substances.