$$X$$ and $$Y$$ are the two atomic species: $$X$$ $$Y$$ Number of Proton $$8$$ $$8$$ Number of Neutron $$8$$ $$10$$ Select the correct statement about $$X$$ and $$Y$$.

$$X$$ and $$Y$$ have different physical properties

$$X$$ and $$Y$$ have different chemical properties

$$X$$ and $$Y$$ are the atoms of different elements

MCQ Questions for Class 11 Medical Chemistry Structure Of Atom Quiz 1

The magnetic field at the center of a hydrogen atom due to the motion of electron varies with the principal quantum number as

0%
$n^{5}$
0%
$n^{3}$
0%
$1/n^{5}$
0%
$1/n^{3}$

The equivalent weight of a metal is 4.5 and the molecular weight of its chloride isFind the atomic weight of the metal.

0%
9
0%
12
0%
15
0%
18

Which of the following statements about the radioactivity of an element is incorrect?

0%
It is a nuclear property
0%
It does not involve any rearrangement of electrons
0%
Its rate is affected by change in temperature and/or pressure
0%
It remains unaffected by the presence of other element or elements chemically combined with it

The Bohr model for the spectra of a H- atom

0%
will not be applicable to hydrogen in the molecular from.
0%
Will not be applicable for a He - atom
0%
is valid only at room tempreture.
0%
predicts continuous as well as discrete spectral lines.

An element 'A' emits an

$\alpha$ -particle and forms 'B'. 'A' and 'B' are

0%
Isotopes
0%
Isobars
0%
Isotones
0%
Isodiapheres

Ejection of the photoelectron from metal in the photoelectric effect experiment can be stopped by applying

$0.5\ V$ when the radiation of

$250\ nm$ is used. The work function of the metal is:

0%
$5.5\ eV$
0%
$4\ eV$
0%
$5\ eV$
0%
$4.5\ eV$

Explanation

From Ejection photoelectron

$\because hv = hv_o + K.E.$

$\dfrac{hv}{x} = \phi+\text{Stopping pot}$

$\therefore \phi = \dfrac{hc}{x} - S.P.$

$=\dfrac{6.6\times 10^{-34} \times 3\times 10^8}{250\times 10^{-9}\times 1.6\times 10^{-19}}-0.5\times 1.6\times 10^{-10}$

$=\dfrac{6.6\times 3}{250\times 1.6} \times 10^2-0.5$

$=4.95 - 0.5$

$\sim 4.5 eV$

Which of the following has the correct combination considering

$List-I$ and

$List-II$ ?

0%
$(II),(R)$
0%
$(II),(Q)$
0%
$(I),(P)$
0%
$(I),(T)$

Explanation

The kinetic energy of the electron in the

$n^{th}$ orbit is given as:

$K.E.=\dfrac{me^4}{8{{\epsilon}_0}^2n^2h^2}$

$\therefore \ K.E.\propto n^{-2}$

Similarly,

radius of

$n^{th}$ orbit

$r\propto \dfrac{n^2}{Z}$

Angular momentum

$|L|\propto n$

and Potential energy

$P.E. \propto \dfrac {-Z^2}{n^2}$

For which one of the following, Bohr model is not valid?

0%
Singly ionised helium atom $(He^+)$
0%
Deuteron atom
0%
Singly ionised neon atom $(Ne^+)$
0%
Hydrogen atom

Assertion: Atoms are not electrically neutral.
Reason: Number of protons and electrons are different.

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Assertion and reason both are correct statements and reason is correct explanation for assertion.
0%
Assertion and reason both are correct statements but reason is not correct explanation for assertion.
0%
Assertion is correct statement but reason is wrong statement.
0%
Assertion is wrong statement but reason is correct statement.
0%
Both assertion and reason statements are wrong.

0%
Both Assertion and Reason are correct and Reason is the correct explanation for Assertion.
0%
Both Assertion and Reason are correct but Reason is not the correct explanation for Assertion.
0%
Assertion is correct but Reason is incorrect.
0%
Both Assertion and Reason are incorrect.

Which of the following electronic configurations has maximum energy ?

What would be the radius of second orbit of

${He}^{+}$ ion?

0%
$1.058\mathring { A }$
0%
$3.023\mathring { A }$
0%
$2.068\mathring { A }$
0%
$4.458\mathring { A }$

Explanation

Radius of the nth orbit,

$r_n = 0.529 \dfrac{n^2}{Z}$

$A^o$

For

$He^+$ ion,

$Z = 2$

Radius of 2nd orbit,

$r_2 = 0.529\dfrac{2^2}{2}$

$\implies r_2 = 1.058$

$\mathring A$

$X$ and

$Y$ are the two atomic species:

	$X$	$Y$
Number of Proton	$8$	$8$
Number of Neutron	$8$	$10$

Select the correct statement about

$X$ and

$Y$ .

0%
$X$ and $Y$ are isobars
0%
$X$ and $Y$ have different chemical properties
0%
$X$ and $Y$ have different physical properties
0%
$X$ and $Y$ are the atoms of different elements

Explanation

$_{ 8 }^{ 16 }{ X }$ and

$_{ 8 }^{ 18 }Y$ .

$X$ and

$Y$ have the same atomic numbers but have different mass numbers so they are isotopes. Isotopes have different physical properties (like melting point, boiling point, and the nuclei of some isotopes are unstable or radioactive) but have the same chemical properties.

So, the correct option is

$C$ .

The valence electrons of magnesium is different in ........... quantum number.

0%
$m$
0%
$n$
0%
$l$
0%
$s$

Explanation

The configuration of magnesium is

$1s^2\ 2s^2\ 2p^6\ 3s^2$ .
The outermost electron is in s orbital and is paired.
Therefore, for the two electrons in 3s orbital, only s, spin quantum number is different.

Though the three fundamental particles are present in almost all elements, one element does not have one of them. Identify the particle

0%
neutron
0%
proton
0%
electron
0%
nucleons

Explanation

Neutron is not present in hydrogen. Electronic configuration of hydrogen is 1

$(_1H^1)$ .

According to Bohr hypothesis, discrete quantity is

0%
Momentum
0%
Angular velocity
0%
Potential energy
0%
Angular momentum

Explanation

Bohr's hypothesis:
1) Electrons revolves round the nucleus in water orbits.
2) Orbit of the electron around the nucleus can take only some special values of radius.
3) The energy of the atom as a definite value in these orbits.
4) In this Orbits, Angular momentum (e) of the electron is integral multiple of the plank's constant h divided by

$2n$ i.e.

$l = n \dfrac{h}{2n}$ .

Bohr Magneton value in S.I. Units is:

0%
$9.273\times 10^{-24} erg T^{-1}$
0%
$9.273\times 10^{-24} JT^{-1}$
0%
$9.273\times 10^{-17} JT^{-1}$
0%
$9.273\times 10^{-10} calT^{-1}$

Explanation

1 Bohr Magneton =

$9.273\times 10^{-24} JT^{-1}$

Substances having same number of electrons but different mass is known as:

0%
isotopes
0%
isobars
0%
isotones
0%
allotropes

Bohrs atomic model assumes :

0%
the nucleus is of infinite mass and is at rest
0%
electron in a quantized orbit will not radiate energy
0%
mass of the electron remains constant
0%
all of the above

A proton is identical to:

0%
The nucleus of helium
0%
The nucleus of a hydrogen atom
0%
A molecule of a hydrogen
0%
An atom of hydrogen

Explanation

Hint: A hydrogen atom has an electron and a proton.

Only the proton of a hydrogen atom is present in its nucleus, and a hydrogen atom is the only atom in the periodic table that does not contain a neutron.
So when we consider only the nucleus of the hydrogen atom, it has only proton in it.
So, Proton is identical to the nucleus of a hydrogen atom.

Other options:

A)The nucleus of helium has 2 protons and 2 neutrons.

C)A molecule of hydrogen has two hydrogen atoms.

D) A hydrogen atom has an electron and proton.

Final answer: Option $B$ .

The first model of an atom was given by _____________.

0%
N. Bohr
0%
E. Goldstein
0%
Rutherford
0%
J.J. Thomson

Electron has nearly the equal mass as that of a/an:

0%
proton
0%
neutron
0%
positron
0%
$\alpha$ -particle

Explanation

Positron is the antiparticle counterpart of an electron. Therefore, it has the same mass but opposite charge to that of an electron.

Hence, option

$C$ is correct.

The electrons are filled in various sub levels according to the order of their energies, is known as:

0%
Aufbau principle
0%
Pauli's principle
0%
Hund's rule
0%
$nl^{x}$ principle

Explanation

The order of filling of orbitals from lower energy to higher energy is explained by the Aufbau's principle and the

$n+l$ rule.

Atomic number of platinum is?

0%
68
0%
78
0%
74
0%
64

Element having atomic number 33 belongs to this group?

0%
III
0%
IV
0%
V
0%
VI

Explanation

Electronic configuration of element with atomic number 33 is

$1s^22s^22p^63s^23p^64s^23d^{10}4p^3$ . So, it is a p-block element with 3 electrons in p orbital, therefore it lies in 5 A group or 15 group.

A particle deflects towards negative plate in the presence the electric field. Identify the particle?

0%
Neutron
0%
Electron
0%
X-ray
0%
Proton

Which of the following quantities can only be a whole number?

0%
Atomic radius
0%
Atomic number
0%
Mass number
0%
Equivalent weight

For an atom of a given element, the number of electrons equals to:

0%
the number of protons $+$ number of neutrons
0%
the atomic number of the element
0%
the number of proton $-$ number of neutrons
0%
the mass number of the element

When the 3d orbital is complete, the new electron will enter in:

0%
4p-orbital
0%
4f orbital
0%
4s orbital
0%
4d-orbital

Explanation

According to the Aufbau principle of electron filling in orbitals, the next shell to be filled after the

$3d$ orbital is the

$4p$ orbital.

Hence, the correct option is

$\text{A.}$

Atomic number of calcium is ?

0%
18
0%
19
0%
20
0%
21

Explanation

The number o protons found in the nucleus of an atom of a given element is called atomic number. Elements are placed in periodic table according to their atomic number.

Example:-

(1) Atomic number of Calcium is

$20$

$^{40}_{20}Ca$

(2) Atomic number of Magnesium is

$12$

$^{24}_{12}Mg$

Which of the following has the same number of protons?

0%
Isobars
0%
Isoelectronic
0%
Isotopes
0%
Isotones

Explanation

Isotopes are elements having the same atomic number but different mass numbers. e.g :

$_1H^1,\ _1H^2,\ _1H^3$ are isotopes of hydrogen.

Who is regarded as father of modern chemistry ?

0%
Ruterford
0%
Einstien
0%
Lavoisier
0%
C.V Raman

The electronic configuration of

$He$ is

$2$ and that of oxygen is:

0%
$2,4$
0%
$2,5$
0%
$2,6$
0%
$2,6,1$

Explanation

Electronic configuration of He is

$1s^2$

Therefore corresponding oxygen can be written as,

[He]

$2s^22p^4$

i.e

$1s^22s^22p^4$

i.e

$2,6$

The relation between atomic number (Z) and atomic mass (A) for light elements is given by :

0%
$A=Z$
0%
$A=2Z$
0%
$2A=Z$
0%
$A=4Z$

Explanation

Atomic number (Z) is total no of proton present in nucleus and atomic mass (A) is total no of proton and neutron present in nucleus.
For light atoms till atomic number 20, generally atomic mass is twice the atomic number

$A=2Z$ as

$n=p$

Bohr proposed his atomic model based on :

0%
oil drop experiment
0%
planck's quantum theory
0%
$\alpha$ -ray scattering experiment
0%
experiments on conduction of gases

The quantity of matter present in an object is called its ___________.

0%
weight
0%
volume
0%
mass
0%
density

Which of the following is not true for atomic number?

0%
It indicates the number of protons in the nucleus
0%
It is represented usually by Z
0%
It is identical with the mass number
0%
It is constant for a given element

Which of the following is correct for a proton?

0%
It is a nucleus of deuterium.
0%
It is an ionised hydrogen molecule.
0%
It is an ionised hydrogen atom.
0%
It is an $\alpha$ - particle.

Explanation

Protium

$=$

$_{1}H^{1}$
Hydrogen atom (Protium) contains 1 proton and 1 electron.

$_{1}H^{1} \rightarrow H^{+} + e^{-}$ . Hence,

$H^{+}$ is a proton. Therefore, it is an ionized hydrogen atom.

Sub atomic particles of atoms are:

0%
protons
0%
electrons
0%
neutrons
0%
all of these

αα particle is:

0%
a hydrogen molecule
0%
a helium nucleus
0%
an electron
0%
a proton

Explanation

$\alpha$ particle is a positively charged particle consists of two protons and two neutrons, all held together by the same strong nuclear force that binds the nucleus of an atom, emitted by some radioactive substances and identical to the nucleus of a helium atom. It carries a charge of

$+2$ .

The atomic number of an element is determined by:

0%
the number of electrons in one atom
0%
the number of neutrons in one atom
0%
the valency of the element
0%
the number of protons in one atom

Explanation

Atomic number is the number of protons in the nucleus of an atom and also the total positive charge in the atomic nucleus.

Hence, option

$D$ is correct.

Identify the sub atomic particles of atoms.

0%
Protons
0%
Electrons
0%
Neutrons
0%
All of the above

The atomic number of an element is

$7$ . This implies that its nucleus contains :

0%
$7$ electrons
0%
$7$ protons
0%
$7$ neutrons
0%
$7$ protons and $7$ electrons

Atomic number is given by the number of _____ of an atom.

0%
protons
0%
neutrons
0%
electrons
0%
All of the above

Thomson proposed the model of an atom similar to :

0%
christmas tree
0%
christmas pudding
0%
chocolate
0%
none of the above

All the atoms of same element have same _______.

0%
mass number
0%
atomic number
0%
atomic mass
0%
All of the above

The ratio of energy to frequency of a radiation emitted by an electron is equal to :

0%
wave length
0%
velocity of electron
0%
bohr's radius
0%
planck's constant

Who suggested the distribution of electrons into different orbits of an atom?

0%
E. Goldstein
0%
Ernest Rutherford
0%
Bohr and Bury
0%
Dalton

What makes the atom of one element different from another element's atom ?

0%
Number of protons
0%
Number of electrons
0%
Number of neutrons
0%
Number of ions

Who was the first scientist to propose a model for the structure of an atom?

0%
J.J. Thomson
0%
Dalton
0%
Ernest Rutherford
0%
E. Goldstein

CBSE Questions for Class 11 Medical Chemistry Structure Of Atom Quiz 1 - MCQExams.com

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Practice Class 11 Medical Chemistry Quiz Questions and Answers

CBSE Questions for Class 11 Medical Chemistry Structure Of Atom Quiz 1 - MCQExams.com

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Practice Class 11 Medical Chemistry Quiz Questions and Answers

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