Wednesday, August 27, 2014

How can the human ear differentiate between the sounds ?


 
The sound wave
The sound waves

It is very important to know that the human ear differentiate between the sounds that reach it through the different factors which are the sound pitch , the sound intensity and the sound quality .

 

Friday, August 22, 2014

The nature and the properties of the sound waves


Sound wave
The sound wave

 

The sound

 

You should know that the sound is an external factor that affects the ear causing the sense of hearing . And it produced due to the vibration of the bodies , and it stops when the vibrating bodies stop their vibration .

 

Thursday, August 14, 2014

The importance of the fossils and the suitable conditions for the fossils formation


 
The fossils

The suitable conditions for the fossils formation

 

It is very important to know that the organism body must be buried immediately after death in a medium that preserves it from the decomposition . The organism must have hard skeleton .

 

Monday, August 11, 2014

The types of the fossils and the ways of formation



 
The fossils

The Fossils

 

It is very important to know that the fossils are the traces and the remains of the living organisms which are preserved in the sedimentary rocks .

 

Saturday, August 9, 2014

The water pollutants and the protection of the water from the pollution


 
The water pollution
 

The water pollution 

 

It is very important to know that the water pollution is the addition of any substance to the water which causes continuous gradual change in the water properties and affects the health and the life of the living creatures .

 

Friday, August 1, 2014

The physical and the chemical properties of the water


 
The water

The physical properties of the water 

 

It is very important to know that the water has a higher melting point , boiling point , and heat of vaporization than most common liquid . This fact indicates that there are strong forces of attraction between the adjacent water molecules .