An echocardiogram uses sound waves to produce images of your heart. This commonly used test allows your doctor to see your heart beating and pumping blood. Your doctor can use the images from an echocardiogram to identify heart disease.Depending on what information your doctor needs, you may have one of several types of echocardiograms.his commonly used test allows your doctor to see your heart beating and pumping blood. Your doctor can use the images from an echocardiogram to identify heart disease. Depending on what information your doctor needs, you may have one of several types of echocardiograms.
The octet rule is a chemical rule of thumb that reflects observation that atoms of main-group elements tend to combine in such a way that each atom has eight electrons in its valence shell, giving it the same electronic configuration as a noble gas.he octet rule is a chemical rule of thumb that reflects observation that atoms of main-group elements tend to combine in such a way that each atom has eight electrons in its valence shell, giving it the same electronic configuration as a noble gas.
Written By: Octet, in chemistry, the eight-electron arrangement in the outer electron shell of the noble-gas atoms. This structure is held responsible for the relative inertness of the noble gases and the chemical behaviour of certain other elements.