New atomic clocks are more accurate than those used to define the second, suggesting the definition might need to change ...

In that experiment, University of Chicago physicist Cheng Chin and colleagues coaxed a group of cesium atoms at just a few ...

The thorium atom transition has a frequency roughly one million times higher than the cesium atom's. This means that, although it has been measured with a lower accuracy than the current state-of ...

at least — is 9,192,631,770 periods of the radiation corresponding to the transition between the two hyperfine levels of the ground state of a stationary cesium-133 atom at a temperature of 0K.

In 1967, the second was defined as the equivalent of the time it takes for a cesium 133 atom to oscillate 9,192,631,770 times between the two energy states. Cesium atomic clocks define a second ...

ranges from 0.7 for cesium to 4.0 for fluorine. The higher an element's electronegativity, the stronger its ability to attract electrons and create a partial negative charge. In a chemical bond, the ...