Name the most symmetrical crystal system.

What are crystal systems ?

The number of basic crystal systems are:

What are the different types of cubic crystal systems.

Name the most serious water pollutant.

Express A=((1,2),(2,3) as the sum of a symmetric and a skew symmetric matrix.

In the most simple type of canal system of Porifera, which of the following ways exhibit water flow?

Express A=[[x,a,b],[a,y,c],[b,c,z]] as the sum of a symmetric and a skew symmetric matrix.