Write the atomic number of an element which has mass number $23$ and number of neutrons $12$ in the nucleus.

Vedclass pdf generator app on play store
Vedclass iOS app on app store
(11) The atomic number $(Z)$ is equal to the number of protons in the nucleus of an atom.
The mass number $(A)$ is the sum of the number of protons and the number of neutrons in the nucleus.
$A = \text{Number of Protons} + \text{Number of Neutrons}$
Given:
Mass number $(A)$ = $23$
Number of neutrons = $12$
Substituting the values:
$23 = \text{Number of Protons} + 12$
Number of Protons = $23 - 12 = 11$
Since the number of protons is equal to the atomic number $(Z)$, the atomic number is $11$.

Explore More

Similar Questions

Give reasons for the following:
$(a)$ Ions are more stable than atoms.
$(b)$ Noble gases show low reactivity.

In the Thomson's model of atom,which of the following statements are correct?
$(i)$ The mass of the atom is assumed to be uniformly distributed over the atom.
$(ii)$ The positive charge is assumed to be uniformly distributed over the atom.
$(iii)$ The electrons are uniformly distributed in the positively charged sphere.
$(iv)$ The electrons attract each other to stabilize the atom.

Show diagrammatically the electron distributions in a sodium atom and a sodium ion and also give their atomic number.

State reasons for the following statements:
$(i)$ Some elements possess fractional atomic mass.
$(ii)$ Isotopes of an element have similar chemical properties.
$(iii)$ Noble gases are inert.

Which of the following correctly represents the electronic distribution in the $Mg$ atom?

Vedclass Products

For Students

Vedclass Test Series

Mock tests in real JEE/NEET style with performance analysis. 5-day free trial.

Start Free Trial
For Teachers

Exam Paper Generator

Generate Set A/B/C/D exam papers from 7.5L+ questions in 2 minutes. 3 chapters free.

Try Free
For Institutes

Online Exam Module

Live online exams with unlimited students, 360° analytics & white-label branding.

See Demo