The number of protons, neutrons and electrons in \(\rm _{71}^{175}Lu\), respectively, are :

Concept:

Atomic no. of an element = Total no. of protons present in the nucleus = Total no. of electrons present in the neutral atom

Mass no. of an element = No. of protons + No. of neutrons

So, from the above two equations

No. of protons in Lu = Atomic no. of Lu

No. of neutrons in Lu = Mass no. of Lu - Atomic no. of Lu

No. of electrons in Lu= No. of protons or the atomic no. of Lu

Calculations

Given

\(_{71}^{175}Lu\)

Step 1 - Atomic no. of given element i.e. \(_{71}^{175}Lu \) = 71

Step 2 - Mass no. of  given element i.e. \(_{71}^{175}Lu\)= 175

Step 3 - No. of protons = Atomic no. = 71

Hence, no. of protons in the given element = 71

Step 4 - No of neutrons = Mass no. - Atomic no. 

So, No. of neutrons = 175 - 71 = 104

No. of neutrons in given element = 104

Step 5 - No. of electrons = No. of protons

No. of electrons = 71

Hence, the no. of protons, neutrons, and electrons in \(_{71}^{175}Lu\) is 71, 104, and 71 respectively.

The correct answer is option 3.