• Discovery of charged particles - class-VIII
Back
0

Discovery of charged particles - class-VIII

Description: discovery of charged particles
Number of Questions: 30
Created by:
Tags: chemistry inside the atom atomic structure atomic structure and chemical bonding the structure of the atom structure of the atom the nature of matter
Start the Quiz
Attempted 0/30 Correct 0 Score 0
‹
›

In 1909, __________ discovered nucleus in his famous gold foil experiment.

chemistry the structure of the atom discovery of charged particles the plum pudding atom discovery of electrons and protons

  1. Rutherford

  2. Goldstein

  3. J.J.Thompson

  4. None of the above

Show answer
Correct Option: A
Explanation:

In 1909, Rutherford discovered nucleus in his famous gold foil experiment.

Protons and neutrons are heavier than electrons and reside in the center of the atom, which is called ______ .

chemistry the structure of the atom discovery of charged particles the plum pudding atom discovery of electrons and protons

  1. the nucleus

  2. the Orbit

  3. the orbitals

  4. none of the above

Show answer
Correct Option: A
Explanation:

Protons and neutron are present in the nucleus of the atom residing at the center.

All the mass of the atom resides in the _____ .

chemistry the structure of the atom discovery of charged particles the plum pudding atom discovery of electrons and protons

  1.  nucleus

  2. molecules

  3. ions

  4. orbit

Show answer
Correct Option: A
Explanation:

All the mass of the atom resides in the nucleus.

The fraction occupied by nucleus in an atom is:

chemistry the structure of the atom discovery of charged particles the plum pudding atom discovery of electrons and protons

  1. $1/10^{-10}$

  2. $1/10^8$

  3. $1/10^{-5}$

  4. $1/10^5$

Show answer
Correct Option: D
Explanation:
Radius of atom $\displaystyle  = 10^{-10}$ m
Radius of nucleus $\displaystyle  = 10^{-15}$ m
The fraction occupied by nucleus in an atom $\displaystyle  = \dfrac {10^{-15}}{10^{-10}}=\frac {1}{10^5}$

Which of the following elements has maximum density of nucleus?

chemistry the structure of the atom discovery of charged particles the plum pudding atom discovery of electrons and protons

  1. ${ { _{ 14 }{ Si } } }^{ 30 }$

  2. ${ { _{ 15 }{ P } } }^{ 31 }$

  3. ${ { _{ 8 }{ O } } }^{ 16 }$

  4. All have same desity

Show answer
Correct Option: B
Explanation:
 $Element$  $Atomic$ $number$$(A)$  $Atomic$ $mass$ $number$$(Z)$ no. of proton (A) no. of neutron(2A-Z)
 $Si$  14  30  14  16
 $P$  15  31 15  16 
 $O$  8  16  8  8

The element containing greater number of proton and neutron has greater density, phosphorus has highest density as compared to others.

$P>Si>O$

The radius of an atomic nucleus (say $He$) is of the order of:

chemistry the structure of the atom discovery of charged particles the plum pudding atom discovery of electrons and protons

  1. $10^{-10} cm$

  2. $10^{-13}cm$

  3. $10^{-15}cm$

  4. $10^{-8}cm$

Show answer
Correct Option: B
Explanation:

The size of an atom is of the order, i,e., diameter is $1A$ or $(10^{-10}m)$.
In case of the nuclear size (say He) it is in the order of 1 Fermi or near to $10^{-15} m$

The atomic nucleus contains:

chemistry the structure of the atom discovery of charged particles the plum pudding atom discovery of electrons and protons

  1. protons

  2. neutrons

  3. electrons

  4. photons

Show answer
Correct Option: A,B
Explanation:

The atom is made up of a central core of the nucleus with protons that are positively charged and neutrons that are neutral. The electrons revolve around this central core in orbits.


Hence, option A and B are correct.

The ratio of the "e/m" (specific charge) values of a electron and an $\alpha$-particle is - 

chemistry the structure of the atom discovery of charged particles the plum pudding atom discovery of electrons and protons

  1. $2:1$

  2. $1:1$

  3. $1:2$

  4. none

Show answer
Correct Option: A

The size of nucleus is of the order of 

chemistry the structure of the atom discovery of charged particles the plum pudding atom discovery of electrons and protons

  1. ${10^{ - 12}}\;{\text{m}}$

  2. ${10^{ - 8}}\;{\text{m}}$

  3. ${10^{ - 15}}\;{\text{m}}$

  4. ${10^{ - 10}}\;{\text{m}}$

Show answer
Correct Option: A

Which form of energy is a measure of the electron stability when it is in bound state with nucleus?

chemistry the structure of the atom discovery of charged particles the plum pudding atom discovery of electrons and protons

  1. Potential energy

  2. Kinetic energy

  3. Vibrational energy

  4. Ionization energy

Show answer
Correct Option: D
Explanation:

 Ionization Energy
The energy needed to remove one or more electrons from a neutral atom to form a positively charged ion is a physical property that influences the chemical behavior of the atom.So higher the ionization energy, higher is the stability.

The volume $(V)$ of nucleus of an atom is expressed in terms of mass no. $(A)$ of atom as :

chemistry the structure of the atom discovery of charged particles the plum pudding atom discovery of electrons and protons

  1. $V\propto A$

  2. $V\propto A^{1/3}$

  3. $V\propto A^2$

  4. $V\propto A^3$

Show answer
Correct Option: A
Explanation:

As we know,

$r=r _0\times A^{1/3}$   

where. A is atomic mass no. and
$\displaystyle V _n=\frac{4}{3}\pi r^3$

So, $\displaystyle V _n=\frac{4}{3}\pi[1.33\times 10^{-13}\times A^{1/3}]^3$

$\therefore V _n\propto A\propto mass :no$.

Compared to size of its nucleus, the size of an atom is about :

chemistry the structure of the atom discovery of charged particles the plum pudding atom discovery of electrons and protons

  1. ten times greater

  2. the same

  3. a hundred times greater

  4. one hundred thousand times greater

  5. a thousand times greater

Show answer
Correct Option: D
Explanation:

the radius of nucleus is of the order of $ {10}^{-15} $ whereas the radius of atom is of the order of  $ {10}^{-10} $.

Mirror nuclei are those which have:

chemistry the structure of the atom discovery of charged particles the plum pudding atom discovery of electrons and protons

  1. the same number of protons

  2. the same number of neutrons

  3. the number of protons equal to number of neutrons

  4. the number of neutrons in one equal to the number of protons in the other.

Show answer
Correct Option: D
Explanation:

 Mirror nuclei are nuclei where the number of protons of element one (Z1) equals the number of neutrons of element two (N2).

$\pi $ - mesons are regarded as the nuclear glue to hold up neutrons and protons in nucleus.
chemistry the structure of the atom discovery of charged particles the plum pudding atom discovery of electrons and protons

  1. True

  2. False

Show answer
Correct Option: A
Explanation:

Protons have positive charge. In any nucleus containing two or more protons there will be electrostatic repulsion between the like charges.

In stable nucleus, attractive forces > repulsive forces and in unstable nucleus, attractive forces < repulsive forces.

Meson theory of stability of the nucleus was postulated by the Japanese scientist Yukawa in 1935.
He postulated the existence of a nuclear particle π-meson or pion which acts as a glue binding the protons and neutrons together in the nucleus.

These mesons hold the protons and neutrons together by continuously exchanging position between neutrons and protons in the nucleus. Hence, π-mesons are regarded as the nuclear glue to hold up neutrons and protons in nucleus.

All atoms contain neutrons in their nuclei except:

chemistry the structure of the atom discovery of charged particles the plum pudding atom discovery of electrons and protons

  1. Protium

  2. Helium

  3. Neon

  4. Chlorine

Show answer
Correct Option: A
Explanation:

All atoms except Protium, an isotope of Hydrogen contain neutrons in their nuclei. As Protium has zero neutrons in the nucleus and has mass no 1.


Hence, the correct option is $A$

Outside a nucleus :

chemistry the structure of the atom discovery of charged particles the plum pudding atom discovery of electrons and protons

  1. neutron is stable

  2. proton and neutron both are stable

  3. neutron is unstable

  4. neither neutron nor proton is stable

Show answer
Correct Option: C

The density of nucleus is about _______ times the density of atom.

chemistry the structure of the atom discovery of charged particles the plum pudding atom discovery of electrons and protons

  1. $10^{-14}$

  2. $10^{12}$

  3. $10^{-8}$

  4. $10^{10}$

Show answer
Correct Option: D
Explanation:

The density of nucleus is about $10^{10}$ times the density of atom.
This because the maximum mass of atom is concentrated in nucleus.

The particles present in the nucleus of an atom are :

chemistry the structure of the atom discovery of charged particles the plum pudding atom discovery of electrons and protons

  1. the proton and the electron

  2. the electron and the neutron

  3. the proton and the neutron

  4. none of these

Show answer
Correct Option: C
Explanation:

The particles present in the nucleus of an atom are the proton and the neutron.
Electrons are present outside the nucleus.

The space between a proton and electron in hydrogen atom is :

chemistry the structure of the atom discovery of charged particles the plum pudding atom discovery of electrons and protons

  1. full of air

  2. full of ether

  3. full of electromagnetic radiations

  4. empty

Show answer
Correct Option: D
Explanation:

Hydrogen atom contains one proton in the nucleus and one electron outside the nucleus.
The space between a proton and electron in hydrogen atom is empty.

Nuclides having the same atomic and mass numbers are known as :

chemistry the structure of the atom discovery of charged particles the plum pudding atom discovery of electrons and protons

  1. isotones

  2. isomers

  3. isobars

  4. isotopes

Show answer
Correct Option: B
Explanation:

Nuclides having the same atomic and mass numbers are known as Isomers.

An atom that has an unbalanced ratio of neutrons to protons in the nucleus seeks to become more stable. The unbalanced or unstable atom tries to become more stable by changing the number of neutrons and/or protons in the nucleus. This can happen in several ways:

  • converting neutrons to protons
  • converting protons to neutrons
  • ejecting an alpha particle (two neutrons and two protons) from the nucleus.

 Isotones :any of two or more species of atoms or nuclei that have the same number of neutrons.

Isobars are atoms of different chemical elements that have the same number of nucleons.

Isotopes are variants of a particular chemical element which differ in neutron number, and consequently in nucleon number.

The nucleus of the hydrogen atom is called as:

chemistry the structure of the atom discovery of charged particles the plum pudding atom discovery of electrons and protons

  1. neutron

  2. electron

  3. proton

  4. nucleons

Show answer
Correct Option: C
Explanation:

The nucleus of Hydrogen atom is called as proton as it has only $1$ proton in it . Thus correct answer is option C.

Nucleus is composed of two kinds of subatomic particles: 

chemistry the structure of the atom discovery of charged particles the plum pudding atom discovery of electrons and protons

  1. protons and neutrons

  2. electrons and neutrons

  3. protons and electrons

  4. none of the above

Show answer
Correct Option: A
Explanation:

Nucleus is composed of protons and neutrons.

An atom has two main regions. Which are those?

chemistry the structure of the atom discovery of charged particles the plum pudding atom discovery of electrons and protons

  1. Planetary electrons and energy levels

  2. Nucleus and kernel

  3. Principal energy levels and energy sublevels

  4. Nucleus and energy levels

Show answer
Correct Option: D
Explanation:

An atom has two main regions, these include nucleus and energy levels.
Nucleus contains protons and neutrons. Electrons revolve in circular energy levels.

The nucleus of the atom consists of:

chemistry the structure of the atom discovery of charged particles the plum pudding atom discovery of electrons and protons

  1. protons and neutrons

  2. protons and electrons

  3. neutrons and electrons

  4. protons, neutrons and electrons

Show answer
Correct Option: A
Explanation:

The nucleus of the atom consists of protons and neutrons. Electrons are present in extra nuclear part.
Note: Protons, electrons and neutrons are subatomic particles.

Radius of a nucleus is proportional to:

chemistry the structure of the atom discovery of charged particles the plum pudding atom discovery of electrons and protons

  1. $A$

  2. ${A}^{{1}/{3}}$

  3. ${A}^{2}$

  4. ${A}^{{2}/{3}}$

Show answer
Correct Option: B
Explanation:

Radius of a nucleus is proportional to $\displaystyle {A}^{{1}/{3}}$
$\displaystyle r=(1.4 \times 10^{-15}) \times {A}^{{1}/{3}}$
Where r is the radius of the nucleus with mass number A.
Here, the unit of radius is meters.  

The ratio of the volume of the atom and the volume of the nucleus is:

chemistry the structure of the atom discovery of charged particles the plum pudding atom discovery of electrons and protons

  1. ${10}^{10}$

  2. ${10}^{12}$

  3. ${10}^{15}$

  4. ${10}^{20}$

Show answer
Correct Option: C
Explanation:

The ratio of the volume of the atom and the volume of the nucleus is $\displaystyle 10^{15}$

The radius of an atomic nucleus is of the order of $\displaystyle {10}^{-13} cm$ or $\displaystyle {10}^{-15} m$ or one Fermi unit.

On the other hand, the radius of an atom is of the order of $\displaystyle {10}^{-8} cm$ or $\displaystyle {10}^{-10} m$ or one angstrom unit.

Note:
The radius of nucleus is much smaller than atomic radius.

The ratio of atomic radius to radius of nucleus is $\displaystyle \dfrac {{10}^{-10} m}{{10}^{-15} m}=10^5$

Volume is proportional to cube of radius.

The ratio of atomic radius to radius of nucleus is $\displaystyle  (10^5)^3 = 10^{15}$

Size of the nucleus is:

chemistry the structure of the atom discovery of charged particles the plum pudding atom discovery of electrons and protons

  1. $1A^0$

  2. $10^{-16}m$

  3. $10^{-15}m$

  4. $10^{-14}m$

Show answer
Correct Option: C
Explanation:

According to Rutherford the nucleus size is ${ 10 }^{ -15 }m$.

Size of the atom ranges from $0.1$to $0.5nm$ 

Which is characteristic of unstable nucleus?

chemistry the structure of the atom discovery of charged particles the plum pudding atom discovery of electrons and protons

  1. $n/p$ ratio is high

  2. Low binding energy

  3. High packing fraction

  4. None of these

Show answer
Correct Option: A,B,C
Explanation:

It is the balance of protons and neutrons in a nucleus which determines whether a nucleus will be stable or unstable. Other factors that influence the stability of nucleus are binding energy and high packing fraction. 

So, the characteristics of unstable nucleus are
  1. $\dfrac{n}{p}$ ratio is high
  2. Low binding energy
  3. High packing fraction

The density of nucleus is of the order of:

chemistry the structure of the atom discovery of charged particles the plum pudding atom discovery of electrons and protons

  1. ${ 10 }^{ 5 }kg{ m }^{ -3 }$

  2. ${ 10 }^{ 10 }kg{ m }^{ -3 }$

  3. ${ 10 }^{ 17 }kg{ m }^{ -3 }$

  4. ${ 10 }^{ 25 }kg{ m }^{ -3 }$

Show answer
Correct Option: C
Explanation:

The density of nucleus is about $2.3\times { 10 }^{ 17 }{ ㎏ }/㎥$. The density is same for all nuclei. Thus density of nucleus is of the order ${ 10 }^{ 17 }{ ㎏ }/㎥$

The radius of nucleus is:

chemistry the structure of the atom discovery of charged particles the plum pudding atom discovery of electrons and protons

  1. proportional to its mass number

  2. inversely proportional to its mass number

  3. proportional to the cube root of its mass number

  4. not related to its mass number

Show answer
Correct Option: C
Explanation:
The radius of a nucleus (r) is proportional to the cube root of its mass number (A).
The approximate law is $r = r _0 \times A^{ 1/3 }$
where $r _0 = 1.2 \times 10^{ -15 }\ m$
option C is correct
- Hide questions
ADVERTISEMENT

Find more quizzes from top tags

general knowledge
3615 Quizzes
119858 Questions
 technology
307 Quizzes
36705 Questions
 sports
963 Quizzes
19148 Questions
 history
1187 Quizzes
13475 Questions
 physics
598 Quizzes
13441 Questions
 biology
1160 Quizzes
12174 Questions
 science & technology
551 Quizzes
11015 Questions
 chemistry
490 Quizzes
9892 Questions
 maths
518 Quizzes
9324 Questions
 softskills
0 Quizzes
7131 Questions