MCQ Questions for Class 9 Chemistry Structure Of The Atom Quiz 9

In Rutherford's

$\alpha$ -ray scattering experiment most of the alpha particles:

0%
are deflected by large angles
0%
are deflected by small angles
0%
pass straight through
0%
None of the above

Explanation

In Rutherford's

$\alpha$ -ray scattering experiment, most of the alpha particles pass straight through the foil. This means that most of the space inside an atom is empty.

A few particles were deflected, which is because of the extremely dense tiny nucleus at the centre.

Hence, the correct option is C.

According to J. Chadwick, __________ is not found in hydrogen atom.

0%
neutron
0%
electron
0%
proton
0%
none of the above

Explanation

According to J. Chadwick,

$\text {neutron}$ is not found in hydrogen atom.

___________ experimentally proved the existence of protons in the atom.

0%
None of the above
0%
Goldstein
0%
J.J.Thomson
0%
Chadwick

On the basis of Rutherford's particle scattering experiment, which of the statement is true:

0%
There is a positively charged center in the atom which was termed as nucleus.
0%
Almost all the mass of the atom is concentrated at the nucleus of the atom.
0%
The size of nucleus is very small relative to the size of the atom.
0%
all of the above.

In 1932, ___________ discovered an electrically neutral particle in the atom named as neutron.

0%
Rutherford
0%
James chadwick
0%
J.J. Thomson
0%
none of the above

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

0%
the nucleus
0%
the Orbit
0%
the orbitals
0%
none of the above

The structure of the sodium atom is shown in the figure given alongside. Identify the correct statement.

There are _____________ no. of electrons in L shell.

0%
2
0%
8
0%
11
0%
1

Explanation

L shell is the

$2^{nd}$ innermost shell. As per the diagram the

$2^{nd}$ shell, i.e. the L-shell has 8 electrons.

Which element has twice as many electrons in its second shell as compared to its first shell?

0%
Calcium
0%
Nitrogen
0%
Oxygen
0%
Carbon

Explanation

The electronic configuration of carbon is

$2,\,4$ . It has twice as many electrons in its second shell as compared to the first shell.

Nucleus is composed of two kinds of subatomic particles:

0%
protons and neutrons
0%
electrons and neutrons
0%
protons and electrons
0%
None of the above

Which of the following elements has odd number of electrons in its valence shell?

0%
Hydrogen
0%
Chlorine
0%
Nitrogen
0%
All of the above

Explanation

The electronic configuration of hydrogen is

$1$ . The electronic configuration of chlorine is

$2,\,8,\,7$ . The electronic configuration of nitrogen is

$2,\,5$ . Therefore the valence shell of all the atoms has odd electrons.

Most of the mass of the atom resides in the _____ .

0%
nucleus
0%
protons
0%
neutrons
0%
orbit

The electronic configuration of aluminium is:

0%
$\boxed {\begin{matrix} K& L&M \\ 2&8 & 3\end{matrix} }$
0%
$\boxed {\begin{matrix} K& L&M&N \\ 1&2&8 & 3\end{matrix} }$
0%
$\boxed {\begin{matrix} P&Q&R\\ 2&8 & 3\end{matrix} }$
0%
None of the above

Explanation

Atomic number of aluminium = 13. Therefore number of electrons = 13. Thus, electronic configuration of aluminium is

$\underset{2\quad 8 \quad 3}{K \ L \ M}$ .

Fill in the blank and complete the analogy by choosing correct alternative from the options given.

Neon : (2, 8) : : Argon : _________

0%
(2, 8, 8)
0%
(2, 8, 8, 8)
0%
(2, 8, 18, 8)
0%
(2, 8, 18)

Explanation

The atomic number of Argon is 18. So, the electronic configuration of Argon is 2, 8, 8.

Hence, the correct option is

$A$ .

Which element has three shells with

$5$ electrons in its valence shell?

0%
Nitrogen
0%
Silicon
0%
Phosphorous
0%
Sulphur

Explanation

The electronic configuration of phosphorous is

$2,\,8,\,5$ . Thus it has three shells and

$5$ electrons in its outermost shell.

Hence, option C is correct.

In 1911, __________ came to the conclusion that the atom had a dense nucleus because most of the particles shot straight through, but some of the particles were deflected due to the dense nucleus of the gold atoms.

0%
Thomson
0%
Chadwick
0%
Rutherford
0%
None of the above

According to J.J. Thomson's atomic model, negative charges are embedded in:

0%
a positively charged sphere
0%
a lump of neutral charge
0%
a lump of small atoms
0%
None of the above

Rutherford's alpha-particle scattering experiment was responsible for the discovery of:

0%
atomic nucleus
0%
electron
0%
proton
0%
neutron

In Thomson's plum-pudding model, electrons are not:

0%
negatively charged
0%
present in every type of atom
0%
collected together in the center of the atom
0%
scattered throughout a blob of positively charged material

How would you describe J. J. Thomsons model of the atom?

0%
An atom is indivisible
0%
The atom is composed of only negatively charged particles.
0%
The atom is composed of a positive core with negatively charged particles orbiting the positive core.
0%
The atom is composed of diffused ball of positive charge with negative particles dispersed throughout.

Explanation

The atom is composed of diffuse ball of positive charge with negative particles dispersed throughout like a watermelon where the red part is the positive sphere and the seeds represent negatively charged particles.

Hence, the correct option is $D$ .

How is the number of rings in the Bohr's model of any element determined?

0%
Column number on periodic table
0%
Atomic mass
0%
Row number on periodic table
0%
Atomic number

Which one of the following is electrically neutral?

0%
Electron
0%
Neutron
0%
Proton
0%
None of these

Explanation

$\bf{Hint:}$ An atom is electrically neutral as in an atom the number of protons is equal to the number of electrons.

$\bf{Correct \ Answer:}$ Option

$B$

$\bf{Explanation:}$

An atom consists of three subatomic particles known as electrons, protons, and neutrons.
Both proton and neutron are present inside the nucleus hence do not take part in the chemical reaction.
The nucleus is a positively charged entity because the proton has a positive charge but the neutrons are electrically neutral as neutrons do not have any charge on them.
Electrons revolve around the nucleus and have a negative charge and electrons are rearranged in the chemical reaction.
A carbon atom with its protons, neutrons, and electrons are shown below for reference;

The net charge inside an atom is zero because :

0%
the magnitude of positive charge is more than negative charge inside atom
0%
the magnitude of positive and negative charge is same inside atom
0%
the magnitude of positive and negative charge is same outside atom
0%
the magnitude of positive charge is less than negative charge inside atom

In Thomson's model, _________ are embedded in a positively charged 'soup'.

0%
electrons
0%
neutrons
0%
protons
0%
ions

Which of the following disproved Thomson's model?

0%
The nuclear model of an atom
0%
The electron model of an atom
0%
The atomic model of an atom
0%
None of above

J.J. Thomson received noble prize in the year:

0%
$1900$
0%
$1906$
0%
$1909$
0%
$1920$

Explanation

J.J. Thomson received noble prize in the year

$1906$ for his work on electrical conductivity of gases.

According to Thomson, an atom consists of:

0%
embedded electrons
0%
positively charged uniform sphere
0%
negatively charged nucleus
0%
Both A and B

Atomic number of sodium is 11, it has following electronic configuration:

0%
2(K), 7(L), 2(M)
0%
2(K), 8(L), 1(M)
0%
2(K), 2(L), 7(M)
0%
2(K), 8(L), 2(M)

Explanation

$\text{Hint}:$ The maximum number of electrons in each shell is calculated by the

$2n^2$ formula.

$\bullet$ Atomic number of any neutral element represents the number of protons or electrons present in the atom.

$\bullet$ Electrons are filled in the shell or orbits with an increase in energy level.

K shell, n = 1 Number of electrons =

$2(1)^2 = 2$

L shell, n = 2 Number of electrons =

$2(2)^2 = 8$

M shell, n = 3 Number of electrons =

$3(3)^2 = 18$ and so on.

The atomic number of sodium is 11, So there are 11 electrons and its electronic configuration is 2(K), 8(L), 1(M).

$\text{Correct Answer is option B}$

Thomson's model could not explain the :

0%
stability of an atom
0%
position of nucleus in an atom
0%
scattering of alpha particles
0%
all of above

Thomson's atomic model is also called :

0%
water melon model
0%
christmas pudding model
0%
both a and b
0%
none of above

The entire positive charge of the atom is located in the nucleus while the electrons are distributed in the vacant space around it. This statement was given by Thomson.

0%
True
0%
False

Explanation

$\text False$

Rutherford's atomic model states that the entire positive charge of the atom is located in the nucleus, while the electrons are distributed in the vacant space around it. This statement was given by Rutherford, not by Thomson.

CBSE Questions for Class 9 Chemistry Structure Of The Atom Quiz 9 - MCQExams.com

0:0:1

Practice Class 9 Chemistry Quiz Questions and Answers

CBSE Questions for Class 9 Chemistry Structure Of The Atom Quiz 9 - MCQExams.com

0:0:1

Practice Class 9 Chemistry Quiz Questions and Answers

Support mcqexams.com by disabling your adblocker.