What is the specially shaped crystal that can bent light?

J. j. thomson’s experiment disproved the theory that an atom

If the chemical properties of a substance remain unchanged and appearance or shape of a substance changes it is called a ?

At 20∘c, the hole in an aluminum ring is 2.800 cm in diameter. you need to slip this ring over a steel shaft that has a room-temperature diameter of 2.804 cm . 1. to what common temperature should the ring and the shaft be heated so that the ring will just fit onto the shaft? coefficients of linear thermal expansion of steel and aluminum are 12×10−6 k−1 and23×10−6 k−1 respectively.