Material Properties: Solubility, Hardness & Transparency

• Everyday objects consist of different materials like glass, plastic, metal, wood, cotton, clay, and paper.
• Some objects are made from a single material, while others are made from multiple materials.

Mud and Adobe Bricks

• Mud is a mixture of water and soil, specifically silt and clay.
• Adobe bricks are sun-dried mud bricks used for construction.
• Adobe bricks are eco-friendly, durable, and cost-effective.

Material Properties

Solubility

• Solubility is the ability of a substance to dissolve in water.
• Soluble materials include sugar, salt, soap, and vinegar.
• Insoluble materials include marble, iron, wood, plastic, and glass.

Hardness

• Hardness is the ability to resist deformation such as scratching or bending.
• Soft materials include plastic, rubber, sponge, and cotton.
• Hard materials include diamond, steel, and wood.

Transparency

• Transparency is the ability of an object to allow or block light.
• Transparent materials like glass allow full light to pass through.
• Opaque materials like wood and metal block light.
• Translucent materials like frosted glass partially allow light to pass through.

Electrical Conductance

• Electrical conductance is the ability of a material to allow electricity to pass through it.
• Conductors include metals like silver, copper, aluminum, and iron.
• Insulators like plastic, paper, rubber, and wood block electricity.

Uses of Common Materials

• Metals are used in construction, cookware, and electrical cables.
• Plastics are water-resistant and used in bottles, toys, packaging, insulation, and electronics.
• Wood is strong and used in furniture, construction, musical instruments, matchsticks, and paper.

Natural Fibres

• Natural fibres are obtained from plants or animals and spun into yarn to make fabric.
• Plant-based fibres include cotton, linen, and jute.
• Animal-based fibres include wool and silk.
• Synthetic fibres include nylon and polyester.

Fabric Properties & Burn Test

• Cotton is soft and wrinkles easily; it burns fast and smells like paper when burned.
• Linen is soft and slightly shiny and burns slowly.
• Jute has a rough texture and burns like wood.
• Silk is soft and strong, burns slowly, and smells like burning hair when burned.
• Wool absorbs moisture and is self-extinguishing when burned.