Structure of the Atoms Test

Result

Structure of the Atoms Test - 32

Score
-
out of -
Rank
-
out of -

TIME Taken - -

SHARING IS CARING

If our Website helped you a little, then kindly spread our voice using Social Networks. Spread our word to your readers, friends, teachers, students & all those close ones who deserve to know what you know now.

Weekly Quiz Competition

Question 1
1 / -0

Alpha-particles that come closer to nuclei in Rutherford's alpha particle scattering experiment:

A
are deflected more

B
are deflected less

C
make more collisions

D
None of the above

Solution

In the $$\alpha$$-particle experiment as the alpha particles come closer to the nucleus it deflects more, because $$\alpha$$-particle and the nucleus both are positively charged. And positive charge repel each other and this electrostatic force is inversely squared proportional to the distance between $$\alpha$$-particle and nucleus.
Option 'A' is correct.
Question 2
1 / -0

In Rutherford's scattering experiment which of the following does not happen ?

A
Most of the $$\displaystyle \alpha $$-rays pass through without deflection

B
A few $$\displaystyle \alpha $$-particles pass through the nucleus

C
A few $$\displaystyle \alpha $$-particles are deflected back

D
$$\displaystyle \alpha $$-particles going near the nucleus are slightly deflected

Solution

In Rutherford's scattering experiment,

(1) Most of the rays pass through without deflection. This indicates that most part of the atom is empty space.

(2) A few particles are deflected back. This represents presence of nucleus which is centrally located, solid compact, small part having all positive charge and nearly the whole mass.

(3) Particles going near the nucleus are slightly deflected. However, none of the particles pass through the nucleus.

Hence, $$B$$ is a correct option.
Question 3
1 / -0

Following conclusions were drawn from the given figure :
I. There is a positively charged centre in an atom called the nucleus.
II. An atom consists of a positively charged sphere and the electrons are embedded in it.
III. The electrons revolve around the nucleus in well-defined orbits.
IV. The size of the nucleus is very small as compared to the size of the atom
V. Only certain special orbits known as discrete of electrons are allowed inside the atom.
Choose the correct statements.

A
I, II and III

B
II, III and V

C
I, III and IV

D
All of these

Solution

On the basis of scattering experiments, Rutherford proposed the model of an atom, which is known as the nuclear atomic model. According to this model -
(i) An atom consists of a heavy positively charged nucleus where all the protons are present.
(ii) The volume of the nucleus is very small and is only a minute fraction of the total volume of the atom.
There is empty space around the nucleus called the extranuclear part. In this part electrons are present. The no. of electrons in an atom is always equal to no. of protons present in the nucleus. As the nuclear part of the atom is responsible for the mass of the atom, the extranuclear part is responsible for its volume.
Electrons revolve around the nucleus in closed orbits with high speeds.
Question 4
1 / -0

Which of the following is the characteristic feature of an isotopes?

A
Same number of electrons and protons but different number of neutrons

B
Same number of electrons but different number of protons

C
Same number of neutrons but different number of electrons

D
None of the above

Solution

The characteristic feature of an isotope is that it has the same number of electrons and protons but a different number of neutrons. The number of nucleons (both protons and neutrons) in the nucleus is the atom's mass number, and each isotope of a given element has a different mass number.
For example, carbon has three isotopes $$C^{12}$$, $$C^{13}$$, and $$C^{14}$$. All the three have 6 protons, but their neutron numbers are 6, 7, and, 8 respectively. Hence option A is correct.
Question 5
1 / -0

Rutherford's alpha Scattering experiment showed that:

A
the atoms were smashed up by alpha particles

B
the atoms consisted of protons in a matrix of electrons

C
the nucleus was quite large and positively charged

D
the nucleus was very small and positively charged

Solution

Rutherford demonstrated that an atom contains the new features of high central charge concentrated into very small volume in comparison to the rest of the atom and with this central volume also contains the bulk of the atomic mass of the atom.
Question 6
1 / -0

The radius of an atom is of the order of:

A
10$$^{-12}$$ cm

B
10$$^{-14}$$ cm

C
10$$^{-10}$$ cm

D
10$$^{-8}$$ cm
Question 7
1 / -0

Rutherford's model of atom could not hold good because:

A
it did not account for the stability of an atom

B
the atom did not have a nucleus and an electron

C
it did not account for the attraction between a proton and an electron

D
there is actually no space between the nucleus and the electron

Solution

Rutherford demonstrated that an atom contains the new features of high central charge concentrated into a very small volume in comparison to the rest of the atom and this central volume also contains the bulk of the atomic mass of the atom.

Failure - An electron revolving around the nucleus at an accelerated pace loses energy following a spiral path and ultimately falls into the nucleus but the atoms are stable. So, he could not explain the stability of an atom.
Question 8
1 / -0

Directions For Questions

The Rutherford alpha ray scatlering experiment was one of the most significant experiment in the history of atomic structure. Alpha particles from a radioactive source were allowed to strike a thin gold foil. Alpha particles produce a tiny but visible flash of light when they strike a fluorescent screen. Few alpha particles were found to get deflected by large angles and surprisingly a very few were even found to be back-scattered.
The scattering of alpha particles by the nuclei of an atom can be modeled from coulombic forces of repulsion between the like charges. The scattering process can be treated statically in terms of the cross section for interaction with the nucleus which in considered to be a point charge $$Ze$$ for a detector at a specific angle with respect to be incident beam. The number of particles per unit area striking the detector, $$\displaystyle N(\theta )=\frac{N_{1}nLZ^{2}K^{2}e^{4}}{4r^{2}(KE)^{2}\sin ^{4}(\theta /2)}$$.
$$\displaystyle N_{1}$$ = Number of incident alpha particles
$$n =$$ Atoms per unit volume in garget
$$L =$$ Thickness of target
$$Z =$$ Atomic number of target
$$K =$$ Coulomb's constant
$$e =$$ Electronic charge
$$r =$$ Target to detector distance
$$KE =$$ Kinetic energy of alpha particles
$$\displaystyle \theta =$$ Scattening angle
Individual atoms of gold can be imagined as spheres of certain radii. Packing of these spheres in the following manner makes up the basic building block of all noble metals.

...view full instructions

If the radius of gold (Au) and platinum (Pt) atoms in pm is $$\displaystyle 100\sqrt{2}$$ and $$\displaystyle 90\sqrt{2}$$, respectively, find $$\displaystyle n_{Au}n_{Pt}$$.

A
$$0.52$$

B
$$0.68$$

C
$$0.73$$

D
$$0.74$$

Solution

The number of atoms per unit volume is inversely proportional to the volume of one atom.
$$\displaystyle \frac {n_{Au}}{n_{Pt}} = \dfrac {V_{Pt}}{V_{Au}} =\dfrac {\dfrac {4}{3} \pi r^3_{Pt}}{\dfrac {4}{3} \pi r^3_{Au}}= (\dfrac {r_{Pt}}{r_{Au}})^3 = (\dfrac {90 \sqrt {2}}{100 \sqrt {2}})^3 = 0.73$$
Question 9
1 / -0

The nuclides $$^{40}_{18}Ar$$ and $$^{41}_{19}K$$ are :

A
isotopes

B
isobars

C
isotones

D
none of these

Solution

The two or more species of atoms or nuclei that have the same number of neutrons are called as isotones.

The nuclides $$^{40}_{18}Ar$$ and $$^{41}_{19}K$$ are isotones. Because they have the same number of neutron.

So, the correct option is $$C$$
Question 10
1 / -0

When alpha particles were bombarded on a gold foil, most of the alpha particles passed through undeflected. This result indicates that most of the volume of a gold atom consists of:

A
nucleus

B
neutrons

C
protons

D
unoccupied space

Solution

When alpha particles were bombarded on a gold foil, most of the alpha particles passed through undeflected. This result indicates that most of the volume of a gold atom consists of unoccupied space. This experiment is called the Rutherford experiment. So the answer is D.

User

Question Analysis

Correct -
Wrong -
Skipped -

My Perfomance

Score
-
out of -
Rank
-
out of -

Re-Attempt Weekly Quiz Competition

Structure of the Atoms Test - 32

Result

Structure of the Atoms Test - 32

Score

-

Rank

-

SHARING IS CARING

Question 1

are deflected more

are deflected less

make more collisions

None of the above

Solution

Question 2

Most of the $$\displaystyle \alpha $$-rays pass through without deflection

A few $$\displaystyle \alpha $$-particles pass through the nucleus

A few $$\displaystyle \alpha $$-particles are deflected back

$$\displaystyle \alpha $$-particles going near the nucleus are slightly deflected

Solution

Question 3

I, II and III

II, III and V

I, III and IV

All of these

Solution

Question 4

Same number of electrons and protons but different number of neutrons

Same number of electrons but different number of protons

Same number of neutrons but different number of electrons

None of the above

Solution

Question 5

the atoms were smashed up by alpha particles

the atoms consisted of protons in a matrix of electrons

the nucleus was quite large and positively charged

the nucleus was very small and positively charged

Solution

Question 6

10$$^{-12}$$ cm

10$$^{-14}$$ cm

10$$^{-10}$$ cm

10$$^{-8}$$ cm

Question 7

it did not account for the stability of an atom

the atom did not have a nucleus and an electron

it did not account for the attraction between a proton and an electron

there is actually no space between the nucleus and the electron

Solution

Question 8

$$0.52$$

$$0.68$$

$$0.73$$

$$0.74$$

Solution

Question 9

isotopes

isobars

isotones

none of these

Solution

Question 10

nucleus

neutrons

protons

unoccupied space

Solution

User

Question Analysis

My Perfomance

Score

-

Rank

-

Results Announcement on: coming Monday

Stay Tuned: We’ll update you on your result via email or SMS.