Question

The number of protons, neutrons and electrons in ${}_{58}^{140}Ce$ respectively are

• A. $140,58$ and $58$
• B. $58,58$ and $82$
• C. $58,82$ and $58$
• D. $82,58$ and $58$

Answer 1

The correct option is C $58,82$ and $58$

Number of protons = atomic number $=58$
Number of electrons = Number of protons $=58$
Number of neutron = Mass number – Atomic number
$=140-58=82$