Tag: discovery of subatomic particles

Questions Related to discovery of subatomic particles

Chadwick was able to prove that the neutral particle could not be a photon by bombarding targets other than : 

chemistry what is inside atom discovery of neutrons structure of atoms discovery of subatomic particles

  1. nitrogen

  2. oxygen

  3. hydrogen

  4. carbon

Show answer
Correct Option: C
Explanation:

Chadwick was able to prove that the neutral particle could not be a photon by bombarding targets other than hydrogen.

Name the scientist associated with the discovery of neutron.

chemistry what is inside atom discovery of neutrons structure of atoms discovery of subatomic particles

  1. J.J. Thomson

  2. James Chadwick

  3. Rutherford

  4. Yukawa

Show answer
Correct Option: B
Explanation:

James Chadwick discovered the neutron.

Which of the following is the main cause of late discovery of neutron?

chemistry what is inside atom discovery of neutrons structure of atoms discovery of subatomic particles

  1. Neutron is highly unstable particle

  2. Neutron in nucleus moves very fast

  3. Neutron is charge-less particle

  4. All of the above

Show answer
Correct Option: C
Explanation:

Initially it was believed that the atom consisted of a small massive nucleus with positive charge surrounded by a much larger cloud of negatively charged electrons. Being charge-less particle, neutron did not show their influence in experiments performed for discovery of charged particles electrons and protons.

Which fundamental particle was discovered by bombarding beryllium with alpha particles?

chemistry what is inside atom discovery of neutrons structure of atoms discovery of subatomic particles

  1. Neutrons

  2. Protons

  3. Electrons

  4. Beta particles

Show answer
Correct Option: A
Explanation:

Neutrons were discovered by bombarding beryllium with alpha particles. James Chadwick discovered the neutron in 1932 while working at Cavendish Laboratory.

Which of the following reactions led to the discovery of neutron?

chemistry what is inside atom discovery of neutrons structure of atoms discovery of subatomic particles

  1. $ _6^{12}C+ _1^1H\rightarrow _7^{14}N+ _0^In$

  2. $ _{11}^{5}C+ _1^2D\rightarrow _{6}^{12}C+ _0^In$

  3. $ _4^{9}Be+ _2^4He\rightarrow _6^{12}C+ _0^1n$

  4. $ _4^{8}C+ _2^4He\rightarrow _6^{11}C+ _0^1n$

Show answer
Correct Option: C
Explanation:

In 1930 it was discovered that Be bombarded by alpha particles and emitted stream of radiation. In 1932 Chadwick proposed that the particle is Rutherford's neutron.

$ _{ 2 }^{ 4 }{ \alpha  }+ _{ 4 }^{ 9 }{ Be }\rightarrow _{ 6 }^{ 12 }{ C }+ _{ 0 }^{ 1 }{ n }$

A neutral atom of an element with nuclear charge 11 times and mass 23 times that of hydrogen. Find the ratio of electrons to protons present in its stable ion.

chemistry what is inside atom discovery of neutrons structure of atoms discovery of subatomic particles

  1. 1:1

  2. 5:6

  3. 10:11

  4. 12:11

Show answer
Correct Option: C
Explanation:

Protons in neutral atom = nuclear charge = 11

Electrons in neutral atom = 11
Mass = 23 

Element = Sodium
Ion = $Na^+$
Electrons in ion = 11-1 = 10
Protons in ion = 11
Ratio of electron to proton = 10:11

Chadwick was able to prove that:

chemistry what is inside atom discovery of neutrons structure of atoms discovery of subatomic particles

  1. the radiation causing the ejected particles was much more energetic than could be accounted for by photons

  2. the radiation causing the ejected particles was much less energetic than could be accounted for by photons

  3. the radiation causing the ejected particles was much more energetic than could not be accounted for by photons

  4. the radiation causing the ejected particles was much less energetic than could not be accounted for by photons

Show answer
Correct Option: A
Explanation:

Chadwick was able to prove that the radiation causing the ejected particles was much more energetic than could be accounted for by photons. Initially it was though that the radiation must be gamma rays. But the radiations differed in interaction with hydrocarbons and with elements like helium, lithium, carbon, oxygen, nitrogen etc.

What really occurred when one bombarded beryllium with alpha particles?

chemistry what is inside atom discovery of neutrons structure of atoms discovery of subatomic particles

  1. Formation of a carbon-12 nucleus and the emission of a neutron

  2. Formation carbon-13 nucleus with the emission of a photon

  3. Formation carbon-14 nucleus with the emission of a photon

  4. Formation of a carbon-13 nucleus and the emission of a neutron

Show answer
Correct Option: A
Explanation:

When one bombarded beryllium with alpha particles, a carbon-12 nucleus was formed and a neutron was emitted.
$ _4^9Be + _2^4He \rightarrow _6^{12}C + _0^1n$

Why did Chadwick thought that the emerging particles on radiations were not photons?

chemistry what is inside atom discovery of neutrons structure of atoms discovery of subatomic particles

  1. Energy of the emerging particles was very low as compared to photon

  2. Energy of the emerging particles was equal to photon

  3. Energy of the emerging particles was much more than the photons

  4. None of the above

Show answer
Correct Option: C
Explanation:

Chadwick carried out the experiments, using many different elements as radiation targets besides paraffin. By comparing the energies of particles ejected from all these various targets, Chadwick was able to prove that the radiation causing the ejected particles was much more energetic than could be accounted for by photons.

Neutron is 1842 times heavier than :

chemistry what is inside atom discovery of neutrons structure of atoms discovery of subatomic particles

  1. proton

  2. electron

  3. both A and B

  4. photon

Show answer
Correct Option: B
Explanation:

Mass of neutron is 1.0086654 a.m.u. Neutron is 1842 times heavier than an electron.