Answer: 1.8 x 10^1 or the scientific e notation is: 1.8e1
2h-7 I had that before unless I’m tripping but I did rechecked
The ideal gas law:

p - pressure, n - number of moles, R - the gas constant, T - temperature, V - volume
The volume and temperature of all three containers are the same, so the pressure depends on the number of moles. The greater the number of moles, the higher the pressure.
The mass of gases is 50 g.

The greatest number of moles is in the container with Ar, so there is the highest pressure.
Answer: isotopes
Explanation: I remember this from when I took honors chemistry, they are know as isotopes.