Chemistry Questions

When exposed to certain frequencies of radiation, such as radio waves, the subatomic particles called electrons that orbit an atom's nucleus will "jump" back and forth between energy states. Clocks based on this jumping within atoms can therefore provide an extremely precise way to count seconds.It is no surprise then that the international standard for the length of one second is based on atoms. Since 1967, the official definition of a second is 9,192,631,770 cycles of the radiation that gets an atom of the element called caesium to vibrate between two energy states.

The atomic mass of an element depends upon the number of protons, electrons and neutrons in the atoms which make the elements.

Mercury is the only metal that is in liqid form at room temperature. Caesium, Gallim and Rubidium are also metals that are in liquid form but at slightly high temperature than the room temperature.