According to our current understanding of physics, it is not possible for an object with mass to reach or exceed the speed of light in a vacuum. The theory of special relativity, proposed by Albert Einstein, sets the speed of light in a vacuum as the maximum speed in the universe. As an object with mass accelerates, its energy and momentum increase, but its speed cannot surpass the speed of light.
Temperature is a measure of the average kinetic energy of particles in a substance. As the temperature of a substance increases, the kinetic energy and the average speed of the atoms or molecules also increase. However, this does not imply that the atoms would eventually reach or exceed the speed of light.
As particles approach the speed of light, relativistic effects become significant. Time dilation, length contraction, and other relativistic phenomena occur, making it increasingly difficult to accelerate an object further. The energy required to accelerate an object with mass to the speed of light would become infinite, making it unattainable.
In summary, based on our current understanding of physics, it is not possible for atoms or any objects with mass to reach or exceed the speed of light, regardless of the temperature to which they are subjected.