What is meant by the phrase: "the atmosphere is unstable"?

QUESTION 1

What is meant by the phrase: “the atmosphere is unstable”?

If air is lifted, it will keep rising on its own

There will be clear skies.

If air is lifted, it will sink back down when the lifting force is removed.

Air wants to move from side to side.

QUESTION 2

What conditions produce extreme stability in the atmosphere (an inversion layer)?

The environmental lapse rate has a steeper temperature decline with height than the dry adiabatic lapse rate.

The surface of the earth generates enough heat to cause thunderstorms.

Cold air is at the surface, or put another way, warmer air is above colder air.

The surface is heated by the sun.

QUESTION 3

What is meant by the phrase: “the atmosphere is stable”?

If air is lifted, it will keep rising on its own.

There will be thunderstorms.

If air is lifted, it will sink back down when the lifting force is removed.

Air tries to move against the Coriolis force.

What is meant by the phrase: “the atmosphere is unstable”?