Opaque Objects
Opaque objects are substances that do not allow light to pass through them. When light falls on an opaque object, it gets absorbed or reflected by the object's surface. This means that the light cannot pass through the object and reach the other side. Opaque objects are commonly seen in our daily lives and are used for a variety of purposes.

Examples of Opaque Objects
- Wood: Wood is an example of an opaque object. When light falls on a wooden surface, it gets absorbed or reflected, preventing light from passing through it.
- Metal: Metals such as iron, aluminum, and copper are also opaque objects. They do not allow light to pass through them.
- Plastic: Many types of plastic are opaque and do not transmit light. This property makes them useful for various applications, such as packaging materials.
- Paper: While paper is thin and translucent to some extent, it becomes opaque when multiple layers are stacked together.

Properties of Opaque Objects
- Absorption: Opaque objects absorb light when it falls on their surface. The absorbed light is converted into heat energy.
- Reflection: Opaque objects also reflect light. The reflected light determines the color of the object that we perceive.
- Shadow Formation: When light falls on an opaque object, it casts a shadow on the opposite side. The shadow is formed because the light cannot pass through the object.

Uses of Opaque Objects
- Privacy: Opaque objects are often used to provide privacy. For example, curtains and blinds are made of opaque materials to block the view from outside.
- Protection: Opaque materials are used in various protective gear, such as helmets and sunglasses, to shield the eyes and head from harmful light or objects.
- Light Control: Opaque objects are used to control the amount of light entering a space. For example, curtains or blinds can be adjusted to block or allow light as needed.
- Photography: Opaque materials are used in photography to create backgrounds or to block unwanted light from reaching the subject.

In conclusion, the substance through which light does not pass is called an opaque object. Opaque objects absorb or reflect light, preventing it from passing through them. Examples of opaque objects include wood, metal, plastic, and paper. Opaque objects have various uses, such as providing privacy, protection, and light control.