Ascuba diver’s air tank contains oxygen, helium, and nitrogen at a total pressure of 205 atmospheres. the partial pressure of nitrogen is 143 atmospheres, and the partial pressure of helium is 41 atmospheres. what is the partial pressure of oxygen in the tank? a. 21 atm b. 103 atm c. 307 atm d. 389 atm

Answers are 1,2,4 its correct on edgenuity.

It is a mixture. simply put, a compound must be pure, that is, of only one chemical structure and composition. a mixture is made of different chemical substances (i.e. elements, molecules, compounds) that are not chemically bonded to each other, but instead physically grouped together, as in the case of gasoline (a homogeneous solution).