Tag: the structure of the atom

Quizzes (8) Questions (30)

Questions Related to the structure of the atom

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

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

  1. $V\propto A$
  2. $V\propto A^{1/3}$
  3. $V\propto A^2$
  4. $V\propto A^3$
Reveal answer Fill a bubble to check yourself
A Correct answer
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, $\displaystyle V _n=\frac{4}{3}\pi[1.33\times 10^{-13}\times A^{1/3}]^3$

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

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

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

  1. ten times greater

  2. the same

  3. a hundred times greater

  4. one hundred thousand times greater

  5. a thousand times greater
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

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

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

Mirror nuclei are those which have:

  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.
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

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

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

  1. True

  2. False
Reveal answer Fill a bubble to check yourself
A Correct answer
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.

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

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

  1. isotones

  2. isomers

  3. isobars

  4. isotopes
Reveal answer Fill a bubble to check yourself
B Correct answer
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.