<P> In chemistry and atomic physics , an electron shell , or a principal energy level , may be thought of as an orbit followed by electrons around an atom 's nucleus . The closest shell to the nucleus is called the `` 1 shell '' ( also called `` K shell '' ) , followed by the `` 2 shell '' ( or `` L shell '' ) , then the `` 3 shell '' ( or `` M shell '' ) , and so on farther and farther from the nucleus . The shells correspond with the principal quantum numbers ( n = 1 , 2 , 3 , 4 ... ) or are labeled alphabetically with letters used in the X-ray notation ( K , L , M , ... ) . </P>
<P> In chemistry and atomic physics , an electron shell , or a principal energy level , may be thought of as an orbit followed by electrons around an atom 's nucleus . The closest shell to the nucleus is called the `` 1 shell '' ( also called `` K shell '' ) , followed by the `` 2 shell '' ( or `` L shell '' ) , then the `` 3 shell '' ( or `` M shell '' ) , and so on farther and farther from the nucleus . The shells correspond with the principal quantum numbers ( n = 1 , 2 , 3 , 4 ... ) or are labeled alphabetically with letters used in the X-ray notation ( K , L , M , ... ) . </P>
what are the rings on an atom called
what are the rings on an atom called
electron shell
electron shell