Tag: chemistry

Questions Related to chemistry

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

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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

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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.

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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

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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

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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. $10^{10}$

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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

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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

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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.