How is an atom represented? Why?

Vedclass pdf generator app on play store
Vedclass iOS app on app store
(N/A) An atom is represented by the notation $^A_Z X$,where $X$ is the chemical symbol of the element,$Z$ is the atomic number (number of protons),and $A$ is the mass number (total number of protons and neutrons).
The positive charge in the nucleus is due to the protons. $A$ proton carries one unit of fundamental charge and is stable.
All the electrons of an atom are outside the nucleus and revolve around it in circular orbits due to the electrostatic Coulomb force.
The number of electrons in a neutral atom is equal to the atomic number $Z$. Hence,the total charge of the electrons is $(-Ze)$.
Since the atom is electrically neutral,the total positive charge of the nucleus must be $(+Ze)$. Therefore,the number of protons in the nucleus is equal to the atomic number $Z$.

Explore More

Similar Questions

An alpha particle is accelerated through a potential difference of $10^6 \ V$. Its kinetic energy will be $MeV$.

The distance of closest approach of an alpha particle to a nucleus when the alpha particle moves towards the nucleus with linear momentum $P$ is $d$. What is the distance of closest approach of the alpha particle to the nucleus if the linear momentum of the alpha particle is $1.5 P$?

$\sqrt{d_{1}}$ and $\sqrt{d_{2}}$ are the impact parameters corresponding to scattering angles $60^{\circ}$ and $90^{\circ}$ respectively,when an $\alpha$-particle is approaching a gold nucleus. For $d_{1} = x d_{2}$,the value of $x$ will be . . . . . .

$A$ beam of fast-moving alpha particles was directed towards a thin gold foil. The parts $A'$,$B'$,and $C'$ of the transmitted and reflected beams corresponding to the incident parts $A$,$B$,and $C$ of the beam are shown in the adjoining diagram. The number of alpha particles in:

If the number of alpha particles scattered at an angle of $90^\circ$ is $56$,how many particles will be scattered at an angle of $60^\circ$?

Difficult
View Solution

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