In an atom, electrons a. are located in the nucleusc. travel outside the nucleusb. are paired with neutronsd. are always in the same place in an atom

 In  an  atom  electron travels   outside the  nucleus. 

   electrons  travels  around   the nucleus   in  orbital  but   it is impossible  to  know  both  the speed  and  location  of electron  at the  same time.  Unlike the  proton and neutrons   which are  located inside the nucleus   electrons  are  located  outside the nucleus.

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