Matter : Frequently Asked Questions (F.A.Qs)

1. What is Natural Philosophy or Physics?

Natural Philosophy or Physics is the branch of science

that treats of matter, and of the forces operating upon

it, and of the physical changes thereby produced.

2. What is science?

Science is classified knowledge.

3. What is matter ?

Matter is anything that takes up room.

4. Is this a real definition of  Matter?

It is not, for it simply tells something about matter in-

stead of telling what matter really is.

5. Why then is it given ?

Because, in the present state of human knowledge, we

can tell nothing of the real nature of matter and this

does the next best thing ; it enables us to distinguish

matter from that which is not matter.

6. Give some other " definition " of matter.

Matter is anything that has weight

7. What are the divisions of matter?

Atoms, molecules, and masses.

8. What is an atom ?

The smallest quantity of matter that can enter into com-

bination. It is generally a part of a molecule.

9. How many kinds of atoms are there?

As many as there are " elements," of which we now know

more than seventy. Others will probably be found.

10. Can an atom be divided ?

Atoms are considered indivisible, but the form or consti-

tution of an atom is unknown. The atom is the chemi-

cal unit of matter.

11. What is a molecule?

It is the smallest quantity of matter that can have a sep-

arate existence.

12. How many kinds of molecules are there?

As many as there are kinds of matter. The nature of

the molecule determines the nature of the substance of

which it is a part.

13. Can a molecule be divided ?

Yes, but. only by a chemical process. A molecule is the

physical unit of matter.

14. Give an illustration of a molecule,

A particle of sugar so small that, if it is divided, none of

Its parts will be sugar.

15. What are the parts of a molecule called?

Atoms.

16. How many atoms are there in a molecule ?

Chemistry teaches that in the case of a very few of th«

elements, the molecule consists of a single atom, but

in almost every case, the molecule contains two or

more atoms. The common sugar molecule has 45

atoms ; the oxygen molecule has two atoms.

17. What is a mass?

A body of matter consisting of two or more molecules;

it is not necessarily very massive.

18. Give an illustration of a** mass " of matter,

A minute dust speck, a mountain or a planet

19. What is an element or an elementary substance ?

A substance, all of the atoms of which are alike, /. e,, one

composed of a single kind of atoms. Silver is an ele-

ment because all of its atoms are silver atoms ; it can-

not by any known or conceivable process be " analysed "

or decomposed.

20. What is a compound substance ?

One that contains more than one kind of atoms. One of

its molecules is like its other molecules, but each mole-

cule contains more than one kind of atoms. Thus, a

dew-drop is composed of many similar water molecules.

but each of the molecules is composed of one oxygen and

two hydrogen atoms. Hence, water in any quantity is

a compound substance. Compound substances are in-

numerable.

21. What is a physical change ?

One that does not change the structure of the molecule

of which the changed body is composed.

22. Illustrate the meaning of " physical change. "

A black iron nail may be made red-hot. The iron mole-

cules jostle one another more vigorously than before,

and the energy of their mutual thrusts we call heat. A

certain kind of motion produced by such increased

activity of the molecules we call light, but the mole-

cules themselves are simply iron molecules, just as

they were at first. The molecule is one thing; the

motion of the molecule is a wholly different thing.

By increasing the molecular motions^ we may even

melt the iron, but that will not change the mole-

cules ; it will simply be melted iron. Two such nails

may be united by welding. The identical molecules

are preserved, and with unchanged identity. With a

file, some of these may be torn away from others, but

each of the filings will be /V^w-filings, composed of un-

changed iron molecules. Hence all of these are physi-

cal changes.

23. With this idea of heat as a mode of motion  give another

 definition of molecule,

A molecule is an aggregation of material particles that

do not part company during the journey of a heat vi-

bration.

24. State and illustrate some change of matter that is not a

 physical change.

If the iron is treated with sulphuric acid, the iron atoms

in each iron molecule will be torn asunder. Each iron

atom will be joined to an atom of sulphur, and four

atoms of oxygen, to make a molecule of iron-sulphate

(green vitriol). We no longer have an iron molecule,

and hence, no iron. Iron and iron-sulphate are essen-

tially diflFerent. Changes that thus alter the constitu-

tion of the molecule, and hence, the nature of the sub-

stance, are chemical changes.

25. What objection is there to the term " Natural Philosophy ? "

There is a philosophy of mind as well as a philosophy of

matter, and one pertains as mostli to Nature as the

other. But the term "Natural Philosophy," with its

restricted significance, is so completely worked into

our language and literature that it would be difficult to

change the usage. The term ** Physics " is preferable.