In 1995, physicists Eric Cornell and Carl Wieman created the first Bose-Einstein condensate (BEC) using which isotope?

Correct option is C

The correct answer is (c) Rubidium-87.
Explanation:
· Bose–Einstein Condensate (BEC): A state of matter that occurs when a gas of bosons is cooled to temperatures very near absolute zero (typically less than a few hundred nano-Kelvins).
· At this temperature, a large fraction of the bosons occupy the lowest quantum state, and quantum mechanical effects become apparent on a macroscopic scale.

· Discovery: In 1995, Eric Cornell and Carl Wieman, along with their team at JILA in Colorado, successfully created the first true BEC using a gas of approximately 2,000 rubidium-87 atoms.
· Significance: This experimental realization confirmed a prediction made by Albert Einstein and Satyendra Nath Bose in the 1920s. For this achievement, Cornell, Wieman, and Wolfgang Ketterle (who created a BEC using sodium atoms shortly after) were awarded the Nobel Prize in Physics in 2001.
Information Booster:
· Isotopes Used:
· Rubidium-87 (Rb-87): Used by Cornell and Wieman for the first BEC.
· Sodium-23 (Na-23): Used by Wolfgang Ketterle and his team at MIT to create another BEC soon after.
· Method: They used a combination of laser cooling (to slow the atoms down) and evaporative cooling (to selectively remove the hottest atoms) to reach the required ultra-low temperatures.