In gas chromatography, the stationary phase is made up of high molecular weight non-volatile polymer coated on solid support packed inside a column and the mobile phase is an inert gas that carries the volatilized components of the sample mixture through the column toward the detector. The physical form of the stationary (s) and mobile phase (m) in gas chromatography are:

liquid (s), gas (m)

Explanation:

In gas chromatography, the phase of stationary would be made of great molecular weight that have non-volatile coated on the packed i.e. inside a column also the mobile phase represent the inert gas that carries the components that should be volatilized.

Now the physical form and the mobile phase is the liquid and the gas

The same would be relevant and considered too

radioactive decay occurs in unstable atomic nuclei – that is, ones that don't have enough binding energy to hold

the nucleus together due to an excess of either protons or neutrons.

the correct answer is:

a. formation of precipitation