Carbonate groups contain a single carbon atom, and three oxygen atoms in a trigonal molecular geometry. The carbon atom has two single bonds to two oxygen atoms and a double bond to the third oxygen atom. Therefore, in addition to carbon, carbonate minerals contain oxygen. An example of a carbonate mineral is calcium carbonate, often found within rocks.
Diffusion is the random movement of molecules or particles from a region of high concentration to a region of low concentration bringing a natural flow in the system. Diffusion ensures that there is a state of equilibrium in the number of molecules in the system.
I think at Approximately 7 years the child should be able to use each hand independently. Hand control is the ability by a child to accurately use and manipulate objects, utensils, tools and even finger in isolation for functional tsak performance.