Away measurable or visible way of describing something

measure its mass

look at its colours to tell the differences

size

shape

4.7 atm

Explanation:

From the question given above, the following data were obtained:

Total pressure (P) = 15.3 atm

Pressure of Helium, P(He) = 3.2 atm

Pressure of Oxygen, P(O) = 7.4 atm

Pressure of Argon, P(Ar) =?

The pressure of Argon, P(Ar) in the tank can be obtained as illustrated below:

P = P(He) + P(O) + P(Ar)

15.3 = 3.2 + 7.4 + P(Ar)

15.3 = 10.6 + P(Ar)

Collect like terms

15.3 – 10.6 = P(Ar)

4.7 = P(Ar)

P(Ar) = 4.7 atm

Therefore, the pressure of Argon, P(Ar) in the tank is 4.7 atm