Chapter 10 — This World of Things

Chapter 10 of the Class 3 The World Around Us (EVS) NCERT textbook (Our Wondrous World), "This World of Things", teaches young learners to observe everyday objects closely, identify what materials they are made of and where those materials come from, and understand key properties of materials such as transparency, flexibility, hardness, and whether they are solid, liquid, or gas, as well as the difference between natural and artificial things.

• Materials and Their Sources — Everyday objects like tables and chairs are made of wood from trees, door hinges and nails are made of metals extracted from rocks called ore, windowpanes are made of glass which comes mostly from sand, and electric switches are made of plastic. Children learn to trace each material back to its source in nature.
• Transparent, Translucent, and Opaque — Materials you can see through clearly, like most glass, are called transparent. Materials you can only partially see through are called translucent. Materials you cannot see through at all, like wood, are called opaque.
• Solids, Liquids, and Gases — Things that keep their shape, such as stones and wood, are solids. Things that flow but stay in a container, like water, are liquids. Things that cannot be held in an open cup because they float freely, like air, are gases.
• Natural and Artificial Things — Things that exist in nature without being made by humans, such as trees, rocks, water, and animals, are called natural. Things that people make, such as clothes, shoes, and tables, are called artificial.

1. 01Metals are extracted from rocks and sediment called ore dug from inside the Earth.
2. 02Glass is mostly made of sand and is transparent, meaning you can see through it clearly.
3. 03Materials can be transparent (clear glass), translucent (partially see-through), or opaque (cannot see through, like wood).
4. 04Wood is hard and rigid while fabric is soft and flexible, which is why each material is used for different objects.
5. 05Objects can be classified as solids (keep their shape), liquids (flow and take the shape of a container), or gases (float freely like air).
6. 06Natural things such as plants, animals, rocks, and water exist without human involvement, while artificial things like clothes and furniture are made by people.
7. 07The same material can have different properties — smoothness, shininess, the sounds it makes when tapped — which help us identify and choose materials for different uses.