Isotopes are atoms of the same element (that is, with the same number of protons in their atomic nucleus), but having different numbers of neutrons. Most (66 of 94) naturally occurring elements have more than one stable isotope.here are 80 elements that have at least one stable isotope and 38 that have exclusively radioactive isotopes, which decay over time into other elements. Iron is the most abundant element (by mass) making up the Earth, while oxygen is the most common element in the crust of the earth.
This test, often called an echo, shows your heart's movement. During this exam, your doctor places a wand on the surface of your chest. It sends ultrasound waves that show pictures of your heart's valves and chambers. Those images let your doctor look at how well your ticker is pumping. Your doctor may combine an echocardiogram with tests called Doppler ultrasound and color Doppler to check blood flow across your heart's valves. Ejection fraction (EF). It's a measure of how much blood is pumped out of your heart each time it beats.
Echocardiogram. Guide. An echocardiogram (also called an echo) is a type of ultrasound test that uses high-pitched sound waves that are sent through a device called a transducer. The device picks up echoes of the sound waves as they bounce off the different parts of your heart. Check the ability of your heart chambers to pump blood (cardiac performance). 2  During an echocardiogram, your doctor can calculate how much blood your heart is pumping during each heartbeat (ejection fraction). 3  You might have a low ejection fraction if you have heart failure.