Question

why is absolute zero theoretical? all particles in a sample can never stop moving. all particles in a sample can never all be moving at once. zero degrees celsius is impossible.

Explanation:

Absolute zero is the lowest possible temperature where particles have minimal motion. According to the third law of thermodynamics, it's impossible to reach absolute zero because particles can never completely stop moving. The first option correctly states this principle. The second option is incorrect as particles can move simultaneously. The third option is wrong because zero degrees Celsius is a real temperature (it's just not absolute zero).

Answer:

All particles in a sample can never stop moving.