Notes On Types of Media - CBSE Class 6 Science
Luminous Objects Objects that emit light on their own are called luminous objects. The light emitted by luminous objects enables us to see things around us. Examples of luminous objects are a tubelight, the sun, a lit candle, a glowing bulb, a bonfire and a lit torch. Non-luminous Objects Objects that do not emit light on their own are called non-luminous objects. The light emitted by luminous objects falls on non-luminous objects, and then bounces back to our eyes, which enables us to see non-luminous objects. Examples of non-luminous objects are the moon, a book, a pen, a wooden box, a cupboard and a chair. Light travels in a straight line, and its rays represent the path of light. The material that light passes through is called a medium.  Opaque Objects Objects through which we cannot see anything are called opaque objects. A medium that does not allow light to pass through it is called an opaque medium. Examples of opaque objects are a pencil box, a wooden screen, a book, a towel, a ceramic plate and chart paper. Most objects in our surroundings, like buildings and trees, are opaque objects. Transparent Objects Objects through which we can see clearly are called transparent objects. A medium that allows all the light incident on it to pass through it is called a transparent medium. Examples of transparent objects are a plain glass plate, a clear plastic scale, windowpanes, a soap bubble, and pure water. Translucent Objects Objects through which we cannot see the objects on the other side clearly but can see some light are called translucent objects. A medium that allows only a part of the light incident on it to pass through it is called a translucent medium.  Examples of translucent objects  are ground glass, frosted glass, smoked glass, sun glasses and butter paper.

#### Summary

Luminous Objects Objects that emit light on their own are called luminous objects. The light emitted by luminous objects enables us to see things around us. Examples of luminous objects are a tubelight, the sun, a lit candle, a glowing bulb, a bonfire and a lit torch. Non-luminous Objects Objects that do not emit light on their own are called non-luminous objects. The light emitted by luminous objects falls on non-luminous objects, and then bounces back to our eyes, which enables us to see non-luminous objects. Examples of non-luminous objects are the moon, a book, a pen, a wooden box, a cupboard and a chair. Light travels in a straight line, and its rays represent the path of light. The material that light passes through is called a medium.  Opaque Objects Objects through which we cannot see anything are called opaque objects. A medium that does not allow light to pass through it is called an opaque medium. Examples of opaque objects are a pencil box, a wooden screen, a book, a towel, a ceramic plate and chart paper. Most objects in our surroundings, like buildings and trees, are opaque objects. Transparent Objects Objects through which we can see clearly are called transparent objects. A medium that allows all the light incident on it to pass through it is called a transparent medium. Examples of transparent objects are a plain glass plate, a clear plastic scale, windowpanes, a soap bubble, and pure water. Translucent Objects Objects through which we cannot see the objects on the other side clearly but can see some light are called translucent objects. A medium that allows only a part of the light incident on it to pass through it is called a translucent medium.  Examples of translucent objects  are ground glass, frosted glass, smoked glass, sun glasses and butter paper.

#### Activities

Activity 1 Learnthings.co.za has created a good animation that simulates that transparent and translucent materials let light through, whereas opaque materials do not.  If an opaque material is put in front of a light source, it blocks the light and a shadow forms. A shadow made by the sun will change in length and position throughout the day.   We can explore that the size of the shadow at different times of the day changes by changing the height of the stick by dragging it up and down.  Go to Actitivity http://www.bootslearningstore.com/ks2/sunfun2.html