$(A)$ The ion $X^{2-}$ has $10$ electrons, which means it has gained $2$ electrons to form the ion.Therefore, the number of protons in the neutral ato

Name: Exam Paper Generator | JEE NEET Paper Generator | Vedclass
Brand: Vedclass
Rating: 5 (35 reviews)

Atomic number $= 8$, Mass number $= 16$

$(A)$ The ion $X^{2-}$ has $10$ electrons, which means it has gained $2$ electrons to form the ion.Therefore, the number of protons in the neutral atom $X$ is $10 - 2 = 8$.Atomic number is equal to the number of protons, so the atomic number of $X$ is $8$.Mass number is the sum of protons and neutrons.Mass number $= \text{Number of protons} + \text{Number of neutrons} = 8 + 8 = 16$.

Class 9 Science STRUCTURE OF THE ATOM Mix Example - STRUCTURE OF THE ATOM

Easy

An ion $X^{2-}$ contains $10$ electrons and $8$ neutrons. What are the atomic number and mass number of element $X$?

A
Atomic number $= 8$, Mass number $= 16$
B
Atomic number $= 10$, Mass number $= 18$
C
Atomic number $= 8$, Mass number $= 18$
D
Atomic number $= 10$, Mass number $= 16$

Explore More

Browse All

Question Bank

All Subjects

Class 9 Questions

Class 9

Science Questions

Chapter

STRUCTURE OF THE ATOM

Subtopic

Mix Example - STRUCTURE OF THE ATOM

$A, B$ and $C$ are three metals with atomic numbers $4, 11$ and $13$ respectively. Arrange the metals in the increasing order of their valency.

Medium

View Solution

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.

Easy

View Solution

What is the valency of $(a)$ aluminium in aluminium sulphate,and $(b)$ sodium in sodium sulphate?

Medium

View Solution

$(a)$ Explain Bohr$-$Bury rules for the distribution of electrons into different shells.
$(b)$ Write the electronic configuration of an atom of sulphur. Also,draw a schematic diagram of its atom showing the distribution of electrons in its shells.

Medium

View Solution

Mention the postulates of Niels Bohr put forth to overcome the objections raised against Rutherford's atomic model.

Medium

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

An ion $X^{2-}$ contains $10$ electrons and $8$ neutrons. What are the atomic number and mass number of element $X$?

Similar Questions

$A, B$ and $C$ are three metals with atomic numbers $4, 11$ and $13$ respectively. Arrange the metals in the increasing order of their valency.

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.

What is the valency of $(a)$ aluminium in aluminium sulphate,and $(b)$ sodium in sodium sulphate?

$(a)$ Explain Bohr$-$Bury rules for the distribution of electrons into different shells.$(b)$ Write the electronic configuration of an atom of sulphur. Also,draw a schematic diagram of its atom showing the distribution of electrons in its shells.

Mention the postulates of Niels Bohr put forth to overcome the objections raised against Rutherford's atomic model.

Vedclass Test Series

Exam Paper Generator

Online Exam Module

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.

$(a)$ Explain Bohr$-$Bury rules for the distribution of electrons into different shells.
$(b)$ Write the electronic configuration of an atom of sulphur. Also,draw a schematic diagram of its atom showing the distribution of electrons in its shells.