In a radioactive decay, an emitted electron comes from
(a) the nucleus of atom
(b) the orbit with principal quantum number 1
(c) the inner orbital of the atom
(d) the outermost orbit of the atom

Options

A. the nucleus of atom
B. the orbit with principal quantum number 1
C. the inner orbital of the atom
D. the outermost orbit of the atom

Answer

A

Explanation

When a radioactive leements emits and electron then one neutron in the nucleus change into poroton so atomic number increase by one unit
`_(91)Pa^(234)rarr_(94)U^(234)+_(-1)e^(0)`
In nucleus the following reaction takes place
`_(0)n^(1)rarr_(1)H^(1)_(-1)H^(1)+_(-1)e^(0)`