Chapter 6 Material Around Us
- Observing objects around you
Solving and Sheita observe a variety of items used daily, such as notebooks and pens. Their teacher, Madam Vidya, helps them understand what these objects are made of.
Everything around us is made of some type of material, such as paper, metal, plastic, wood, glass, etc. These materials differ in terms of their properties such as color, hardness, size, and weight.
- Identification of Materials
Substances are the substances from which things are made.
They have been asked to make a list of the items around them and write the names of the materials used in the manufacture of those items. Examples: Plastic chairs, paper books, glass bottles, etc.
By observing objects, students learn that different materials are used for different objects based on the required properties.
- Grouping of materials on the basis of properties
Objects can be classified based on similarities in their properties. Properties such as shape, color, texture (smooth or rough), hardness (hard or soft), and type of material (metal, plastic, etc.) are used to classify objects.
Grouping objects shown in the figure based on properties such as hardness, softness, or brightness. This process of grouping is called classification.
For example, soft objects such as cotton or sponges are classified as soft, while hard objects such as stones are classified as hard.
- Selection of Materials for Manufacture of Objects
Different materials are selected depending on the purpose of the object. For example:
The glass should be made of a material that can hold water (such as glass, plastic, or steel), not a material that can absorb water, such as paper or cloth.
- Different balls for different games
Different sports require balls made of different materials. The cricket ball is hard, while the tennis ball is soft and bounces to a higher height.
- Properties of Substances
Appearance: Substances may look shiny or faded. Shiny materials such as metal (gold, copper)
Whereas faded materials such as wood or plastic are not said to be shiny.
Hardness: Some materials are hard, i.e. they cannot be easily scratched or pressed, such as stones,
Iron or bricks.
Soft materials such as rubber or cotton can be easily pressed or scratched.
Transparency:
Transparent Materials: Objects such as glass, water and some plastics, through which we can see clearly.
You can.
Translucent substances: objects such as butter paper or frost-covered glass, through which light passes
But we can’t see clearly.
Opaque materials: Objects such as wood, metal or cardboard that do not allow light to penetrate through them.
- Grouping of objects on the basis of similar properties
Materials can also be grouped based on their general properties, such as:
Shiny (shiny) or faded (non-shiny)
Hard or soft
Transparent, translucent, or opaque
- Importance of Classification
Classification helps to arrange objects in an orderly manner. It helps in identifying and selecting materials based on their properties for the manufacture of various items.
For example, metals are used to make utensils because they are strong and can tolerate heat.
What is soluble in water; Isn’t it?
Water is important because it can dissolve many substances, making it essential for life.
Making ORS (Oral Rehydration Solution)
ORS is a simple mixture used to treat dehydration. Salt, sugar in it
And there is water, which dissolves completely. It is one of the most useful substances in daily life.
Example.
How heavy or light?
Take three equal cups, fill one with water, one with sand and the other with pebbles. By weighing them, they see that
Mass depends on the amount of matter present in an object.
Objects that weigh more also have more mass.
The heavier an object, the greater its mass.
Location and volume
Volume is the space that an object occupies. When the students compared two glasses filled with different levels of water,
So he saw that the capacitance of both was the same, but the volume of water was different.
Volume of Liquids: Volume is measured in units such as milliliters (ml) or liters (L).
For example, water bottles are labeled for their volume (e.g., 500 mL).
What is matter?
Matter is everything that occupies space and that has mass. All objects around us, whether solid, liquid or gas, are made of matter.
Mass and volume are two properties that define matter. Mass is measured in kilograms (kg) and grams (g), while volume is measured in liters (L) and milliliters (mL).
1 Kilogram (kg) = 1000 grams (g)
1 Liter (L) = 1000 Milliliters (mL)
Examples of Matter
Gases such as air, water, rocks, metals, and even oxygen are examples of matter. Each of these materials occupies space and has a measurable mass.
Grouping of substances based on properties: By studying their properties (e.g., hardness, transparency), we can classify substances. For example, metals are usually hard and lustrous, while plastics are light and soft.