Vitamin K antagonists (VKA) are a group of substances that reduce blood clotting by reducing the action of vitamin K. They are used as anticoagulant medications in the prevention of thrombosis, and in pest control, as rodenticides. 1  1 Mechanism of action.  2 Coumarins (4-hydroxycoumarins)
Calculate the average atomic mass of oxygen. Solution: ((15.994915*99.757) + (16.999132*0.038) + (17.999160*0.205))/100 = 15.999405 . Using our equation for determining average atomic mass, we see that the average atomic mass for oxygen is 15.999405 amu. If we check the periodic table, we will see that our average atomic mass is the same as the atomic mass indicated on the element oxygen. Ã
Report Abuse. Atomic mass is the mass of one atom of an element. example-atomic mass of oxygen is 16 which means that one single atom of oxygen weighs 16 units.Molar mass of oxygen is the weight of 1 mole(Avogadro's No.)of atoms or molecules of oxygen. Anonymous Â· 3 months ago. Thumbs up.