We see a vast variety of objects everywhere around us. Not only food ingredients and clothes but many other objects like a chair, a cycle, cooking utensils books, toys, water, stones, and many other objects are present around us. All these objects have different shapes, colors, and uses. In this blog on sorting materials into groups, we will learn different materialistic properties of objects.

 

Now, look around and identify objects that are round in the shape. Basketball, tennis ball and globe are perfectly round. If we include objects that are nearly round, our list could include objects like apple, oranges, and earthen pitcher.

 

Many objects that we see around us have well-defined shapes like eggs are oval, ice cream cones are conical and bottles are cylindrical in shape. If we wish to make a group of objects that are made of plastics, the objects which may find a place in this group are buckets, lunch boxes, toys, water bottles, etc.

 

You see that there are so many ways to group objects. Sorting materials into groups is easy when you know an object's properties. For example, we have grouped objects on the basis of their shape or the material they are made from, sometimes, the same object can be made of different kinds of material.

 

Your pen could be made up of metal or plastic. Your plate could be made of steel or glass or plastic or other metals. Your shoes could be wooden, metallic, or plastic. You can also see that several objects can be made from the same material. Notebook, newspaper, greeting cards, and the calendar are made from paper.

 

Similarly, your shoes, belt, and bag are made from leather. The objects made from the same type of material can also form a separate group. Let us learn the process of sorting materials into groups based on their properties.

 

Properties of Materials

 

Have you ever wondered why we never use paper-like materials for making cooking vessels? Similarly, a tumbler or a bowl is not made using a piece of cloth. What we need for a tumbler is glass, plastic, metal, or some other material that will hold hot or cold liquids such as water, milk, sharbat, etc.

 

You can observe that we choose a material to make an object depending upon its properties. Let�s see some important properties of materials.

 

Appearances: Materials usually look different from each other. Gold, copper, iron, and aluminum-look shiny and are called Lustrous Materials. Other materials like unpolished wood, a lump of clay, a piece of chalk are Non-lustrous. These are dull in appearance.

 

A Metal like iron may react with the moisture in the air; as a result, it loses its luster and looks dull

 

Hardness: Materials that are hard like iron are difficult to compress, while those that can be compressed or stretched easily are called soft materials. Cotton, plasticine, and sponges are examples of soft materials.

 

Solubility: Solubility is another important property of a material. Substances that completely dissolve in water are said to be soluble in water for example sugar, glucose, common salt, copper salt are soluble in water.

 

Substances like sand, sawdust, etc do not dissolve in water even if you stir them extremely well. They are said to be insoluble in water.

 

Do liquids also dissolve in water?

 

Let�s do an activity to observe this property. Collect samples of lime juice, vinegar, mustard oil and kerosene and try mixing them in water. You will notice that lime juice and vinegar get completely dissolved in water, while mustard oil and kerosene do not mix with water and form a separate layer.

 

Some gases can dissolve in water. For example, oxygen dissolved in water is useful for plants and animals that live underwater. Some objects like stone, flowerpot, etc sink in water, while other objects like bottles, paper boats, etc float on the surface of the water.

 

Those substances or materials through which things can be seen are called transparent materials. Glass, water, air, and some plastics are examples of transparent materials.

 

Materials like wood, cardboard, and metals are opaque as you cannot see through the objects made from these materials. These materials are called Opaque materials.

 

There are some materials that allow you to see through them, though not very clearly, such materials are called Translucent materials. Butter paper and frosted glass are examples of translucent materials.

 

Read More- Separation Of Substances: Sieving, Threshing, Handpicking, & Filtration.