SCIE 4001
Unit 1
Introduction
About Matter
Nature of Matter
Properties of Matter
States of Matter
Kinetic Theory of Gases
 
 
 
Brownian Motion
 

Unit 1-1a - About Matter

MATTER & MATERIALS

This section introduces you to the relationship between matter, materials and objects or things in your environment...

We know that some things around us occupy space and have mass so we can percieve them with the senses....

But do we have clear concepts of objects, matter and materials and their interrelatedness?

What is the difference between an object (e.g. a chair) and a material (e.g. metal or wood)?

Objects are made from materials! For example, my chair is made from more than one material - it has a metal frame, plastic wheels on the legs, a seat and backrest which is covered natural leather sheet over polystyrene foam. Materials are used to make objects. An object can be made from a single material like a crobar made of steel or composite materials like a hammer or knife.

chair

crowbar hammer hammer
Fig 1.1.6 - My Chair
Fig 1.1.7 - Crowbar Fig 1.1.8 - Hammer Fig 1.1.8 - Knives

What are the characteristics or properties of an object?

Consider how we distinguish a chair from related furniture objects like stools, tables, desks, etc...

One of our main criteria is the use of the chair - it is basically for sitting... that is called function...

But is function sufficient to define a chair? Doesn't a stool have the same function?

So if function is not enough we look at the form of the object. Objects take specific forms to satisify their function...

We recognize the chair above by its form (shape) and by its function. But, is it reasonable to say that we generally recognize objects by their form and function?

I think so... When we encounter an object for the first time, our attention may be drawn to its form and we quickly search our minds for functions associated with that particular form. But sometimes we can draw the wrong conclusion as, for example, when shown novelty items or props used in stage shows!

So, which of these (form or function) do we rely on more when identifying an object?

Don't be too quick to say form! Form may be more applicable to objects with which we are familiar... but in identifying unfamilar objects we may resort to funtion... Think about all the gadjets you see nowadays... Is it a toy or phone or tablet or some strange new gizmo for which we have not have a name?

usb link

What is the device in Fig 1.1.10?

Write down your answer!

USB charger for an unknown tablet or cell phone?

Fig 1.1.10 - ????
usb link

Click on Fig 1.1.11 and the image will change. (You may need to enable Active X in your browser)

Does the new image in Fig 1.1.10 help?

BTW... To bring back the old image pass your mouse over here ...

Fig 1.1.11 - ????
usb link

Click on Fig 1.1.12 and the image will change. (You may need to enable Active X in your browser)

When you see the new image in Fig 1.1.12, do you connect the picture to Fig1.1.11 and the words 'High Performance Hard Drive'?

Do you realize it is a hard disk drive for a computer in that box and the picture is that of a hard drive?...

... so the device in Fig 1.1.10 is actually some kind of USB connector for a hard drive to my Computer?...

BTW... To bring back the old image pass your mouse over here...

Fig 1.1.12 - ????

So as we mature and become more experienced we examine objects and find that they are composed of materials. Some of these we get from nature and use in more or lesss their natural state like gravel and sand for builiding roads. But we often employ technology to improve the product by processing and conbining natural materials so that they may not even resemble the original materials. For example, the material used for our road paving is a combination of gravel, sand and bitumen.

So the big question is how do we identify materials?

Materials have physical and chemical characteristics. These properties may make them suitable for making some objects.

Have we answered the question - "What is matter?"

Materials are considered substance objects from which things are made e.g. metals, ceramics, plastics, rubber, wood, glass, cement, leather, bone, textiles, glues, paints, dyes, solvents, foodstuff, medicine etc. Can you add a few more?

Glass is a material from which the following objects are made:

glass
glass
glass
Fig 1.1.13
Fig 1.1.14
Fig 1.1.15
glass
glass
glass
Fig 1.1.16
Fig 1.1.17
Fig 1.1.18

Similarily the following are made of copper:

copper 1
glass
glass
Fig 1.1.18
Fig 1.1.19
Fig 1.1.20
glass
glass
Fig 1.1.21
Fig 1.1.22

 

Main Points

1. Objects are made from one or more materials.

2. Materials are made from elements and compounds.

— iron ore occures in the ground and it is refined and addition of small amounts of other elements like carbon and other metals make it a different material called steel from which many objects are made

— wood is used for making many objects.

petroleum occurs under the ground and when refined it is used to make many products like fuels, oils, plastics, fibres for fabric.

occupy space and have mass

2. Different objects may be made from the saame material or combination of materials.

3. The function as well as the form helps us to identify it.

 

Questions

What is a material?

Does matter and materials have the same meaning?

What are the uses of materials?

 

Activities

— 1. Make a list of the materials used for making the objects around you.

2. Discuss the suitability of the materials used in the objects around you for their expected functions.

3. Demonstrate that materials (especially gases like air) occupy space.

act1

Fig 1.1.23

Resources: large clear plasic drinking glass, length of clear tubing like that used for aquarium pump, shallow dish and water.

1. Read the safety first.

2. Drill a small hole (the same as the outer diameter of the plastic tubing) at the bottom of a transparent plastic drinking glass.

3. Use plastercine to seal the plastic tubing in the hole. Do not let the tubing project into the glass.

4. Cut off a circle of flat polystyrene that will just fit the bottom of the glass.

5. Place the upturned glass in a shallow dish of water.

6. Float the circular ploystyrene under the glass

7. Blow into the tube

8. Observe the bubbles escaping from under the sides of the glass.

Safety:

1. To prevent water from going into the mouth if the investigator breathes in, float the circular ploystyrene under the glass.

2, Do not let the tubing project into the glass.

— 4. Displacement of liquids by solids.

4. Objects have Weight (air has weight)

act1

Fig 1.1.24

Resources: plastic or wooden strips about 1m long, a small strip of wood about 50cm long, block of wood about 30 cm long, two baloons, clear plastic tape, thread, 3 small nails or screws, paper clips and pin.

1. Balance the strip on a knife edge and drill a hole at this point.

2. Attach screws on the ends and attach the strip to the upright with another screw.

3. Blow up the baloons and attach a thread to each so that it ccan be hung from the screw.

4. Place a small square of clear tape on the right baloon.

5. Attach the baloons to the two end screws.

6. Use tape with paper clips to balance the beam.

7. Use a pin to puncture the baloon where you place the square of clear tape, otherwise it would explode and pieces may detatch themselves.

8. Allow the baloon to deflate slowly.

Note: It may appear that the baloon is getting heavier as it deflates if the escaping air shoots upwards, so for best initial results punch the hole in the 'equitorial' region! In any case on complete deflation the arm will rise.

Another method if you have access to a sensitive balance is to inflate a basketball or football and find its mass. Then deflate it and compare the mass.

Placing liquids which do not mix in the same container (measuring cylinder) – pay attention to the child’s intellectual development according to Piaget. If the child does not have the concept of conservation of quantity, it would be dificult to understand.

 

In the next section we will look at the some physical and chemical characteristis we use to identify and classify materials...

 

Concept by Kishore Lal. Programmed by Kishore Lal... Copyright © 2015 Kishore Lal. All rights reserved.