An element can have atoms with different mass numbers but same chemical properties and some are also used in the field of medicine in the treatment of diseases.
-what are such element known as?
-define such elements and also write one example?
-give their one point of difference from isobars?

You exhale co2 which is produced during cellular respiration.  co2 combines with the water in your blood's plasma to make up one half of the body's most important buffer pair, carbonic acid.  the more physical activity you engage in, the more co2 your body is producing.  you can see this by putting some of the cabbage indicator in a glass and then blowing bubbles into it through a straw.  can you see a change in the color of the indicator?