Chapter 6 Materials Around Us PDF

# Materials Around Us ## 6.1 Observing Objects Around Us - Ghulan and Sheeta are excited to start their new class after summer break. - They discuss what they brought to school. - Ghulan brought a new notebook and a pen. - Sheeta brought a new notebook. ## 6.2 How to Group Materials? - Objects c...

# Materials Around Us ## 6.1 Observing Objects Around Us - Ghulan and Sheeta are excited to start their new class after summer break. - They discuss what they brought to school. - Ghulan brought a new notebook and a pen. - Sheeta brought a new notebook. ## 6.2 How to Group Materials? - Objects can be grouped based on properties like shape, color, hardness, softness, shine, dullness or materials they are made up of. - Example: A ball can be made from different materials and some materials can be used for more than one object. - The method of arranging objects into groups is called **classification**. ## 6.3 What are the Different Properties of Materials? ### 6.3.1 Observe and Identify Appearance of Materials - Materials can have different appearances, for example wood looks different than iron, which looks different than copper or aluminium. - There can sometimes be similarities among materials which make them different from others. - Example: Iron, copper, and aluminium are different from wood. - Materials can be sorted by sheen, texture, color, and other noticeable features. - Materials that have shiny surfaces are called **lustrous**. Examples: Iron, copper, zinc, gold and aluminium - **Non-Lustrous** materials do not have a shiny surface. Example: Paper, wood, rubber, jute. ### 6.3.2 Which Materials are Hard? - Materials can be pressed and some are easier to compress than others. - **Hard** materials cannot be compressed easily. Examples: Stones - **Soft** materials can be compressed easily. Example: Erasers. - Hard materials can be used to scratch soft materials. Example: Using a metal key to scratch wood, aluminium, stone, iron, candle, chalk, etc. ### 6.3.3 Explore Materials Through which One can See or Cannot See - Materials can be classified by whether or not one can see through them. - **Transparent** objects can be seen through clearly. Example: Glass, water, air, cellophane paper. - **Opaque** materials cannot be seen through at all. Example: Wood, cardboard and metals. - **Translucent** materials allow one to see through them, but not clearly. Example: Butter paper and frosted glass. ### 6.3.4 What is Soluble in Water? What is Not? - Some materials dissolve completely in water. These are called **soluble**. Example: Sugar and salt. - Some materials do not dissolve in water. These are called **insoluble**. Example: Chalk powder, sand and sawdust. ## 6.4 What is Matter? - All materials have **mass** and **volume**. - **Matter** is anything that occupies space and has mass. - **Mass** is the quantity of matter and is measured in grams (g) and kilograms (kg). - **Volume** is the space occupied by matter and is measured in Liters (L) and milliliters (mL). - **SI System of Units** is used to represent the units of mass, volume, and other quantities. - The abbreviation for **kilogram** is **kg**. - The abbreviation for **liter** is **L** and **milliliter** is **mL**. - The abbreviation for **cubic meter** is **m³**. - Always leave a space between the numerical value and the unit. # Summary - Objects are made from a large variety of materials. - We can group objects together based on shared properties. This is called **classification**. - Materials can be grouped based on appearance, *i.e.*, **lustrous** or **non-lustrous** and based on feel, *i.e.*, **hard** or **soft**. - Materials can be grouped based on transparency, *i.e.*, **transparent** or **opaque**. - Some materials **dissolve** in water and others remain **insoluble** - **Matter** is anything that occupies space and has mass. - **Mass** is the quantity of matter. - **Volume** is the space occupied by matter. # Let us Play **1. Find the Companion** *Connect these words by drawing arrows between them if they describe similar ideas* - Transparent - Solid - Plastic - Iron - Wood - Lustrous - Glass - Copper - Bottle - Opaque **2. Win The Word-hub** Pick nine words from the following list and write them in a grid. Have someone give you a word or definition. Check off the word or definition in your grid. The first person to check off nine words wins. * lustrous * non-lustrous * soluble * insoluble * hard * soft * matter * mass * transparent * opaque * volume * translucent **Let us Enhance Our Learning** **1.** Visit your kitchen and observe how your parents have organized various edibles. Can you suggest a better sorting method? **2.** Unscramble these words and match them with their properties. | Unscrambled Word | Property | |-------------------|-----------| | **Transparent** | Objects can be seen clearly through it | | **Luminous** | Occupies space and has mass | | **Transparent** | Has a shiny surface | | **Soluble** | Mixes completely in water |