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
1 mole of a pure substance has a mass equal to its molecular mass (MM) so 1 mole of a substance x MM with oxygen its molar mass is 15.9994 so if your trying to find HALF â¦ then the equation would be 0.5 x 15.9994 therefore half a mole of oxygen gas will weigh exactly 7.9997 grams approx 8grams google usually helps with these sorts of equations aswell Love Maddi Leicester