OUR ENVIRONMENT AND HOW WE USE IT 13 



The Nature of Matter. The person who considers 

 only plants or animals in relation to their environment 

 might be satisfied to stop with the factors mentioned 

 above. But the scientist wants to know more about the 

 environment. He is not content to know what things 

 do ; he wants to know how they are made. He will tell 

 you that all these factors of the environment as well as 

 the living things found in these are made up of something 

 he calls matter. Matter, according to the scientist of 

 yesterday, was anything that had weight or filled space. 

 But the scientist in our changing world is not content 

 to stop with this definition. He says experiments show 

 him that matter behaves as if it were made up of tiny 

 particles separated by spaces. He can take a hollow iron 

 ball filled with water, which looks quite solid to the human 

 eye, and by subjecting it to great pressure, can squeeze 

 water right through it. This, he says, could not be done 

 unless the iron were built of particles which are not con- 

 tinuous but are separated from each other by spaces. 

 The scientist calls these particles molecules. But he does 

 not stop there. He says that the molecules can be broken 



a molecule 

 of voter 



Read the paragraph on " The Nature of Matter " carefully. The electrons are repre- 

 sented by dots and the protons by small circles. Can you explain this diagram ? 



