MCQExams
0:0:1
CBSE
JEE
NTSE
NEET
Practice
Homework
×
CBSE Questions for Class 10 Chemistry Periodic Classification Of Elements Quiz 3 - MCQExams.com
CBSE
Class 10 Chemistry
Periodic Classification Of Elements
Quiz 3
The total number of inert gases among the following is:
H, He, Ne, F, Ar, Kr, K
Report Question
0%
1
0%
2
0%
3
0%
4
Explanation
From periodic table, it can be seen that the
total number of inert gases is six.
Helium (He); Neon ( Ne); Argon (Ar); Krypton (Kr); Xenon (Xe); Radon (Rn). So, total number of inert gases among the following is 4.
Arrange the following elements in the order of their decreasing metallic character.
$$Na,\ Si,\ Cl,\ Mg,\ Al$$
Report Question
0%
$$Cl > Si >Al > Mg >Na$$
0%
$$Na >Mg >Al >Si > Cl$$
0%
$$Na > Al > Mg > Cl > Si$$
0%
$$Al > Na> Si > Ca> Mg$$
Explanation
Metallic character depends upon the ability to lose electrons. Metallic character decreases, on moving from left to right in a period because the force of attraction between the nucleus and the outermost electron increases thereby the atomic size decreases. Therefore, it becomes difficult for the metal to lose electrons from the outermost shell.
Therefore, the order is $$Na>Mg>Al>Si>Cl$$.
Mendeleev predicted the existence of certain elements not known at that time and named as Eka-aluminiumT he elements which have taken the place of Eka-aluminium is :
Report Question
0%
Germanium
0%
Gallium
0%
Silicon
0%
Aluminium
Explanation
Eka-silicon means germanium. It occurred because of silicon whereas eka-aluminium occurred because of aluminium and later named it gallium.
While filling the elements considering atomic number would be main and fundamental property there were gaps in the mentioned groups hence he filled them with these names.
Hence the correct option is $$B$$.
Which among the following elements has the largest atomic radii?
Report Question
0%
$$Na$$
0%
$$Mg$$
0%
$$K$$
0%
$$Ca$$
Explanation
The atomic radii increase down the group and decrease across a period.
Among the given options, the atomic radii will increase in the following order: $$Mg<Na<Ca<K$$.
The period of element with atomic number 20 in the periodic table is:
Report Question
0%
1
0%
2
0%
3
0%
4
Explanation
Atomic number with 20: (electronic configuration) 2, 8, 8, 2. The total number of shells are four, therefore it will belong to the fourth period.
Hence the correct option is D.
The group number of element with atomic number 7 in the periodic table is:
Report Question
0%
2
0%
18
0%
15
0%
14
Explanation
Atomic no. $$7$$ is Nitrogen which is in group $$15.$$
Which group of elements could be placed in Mendeleev's Periodic Table without disturbing the original order?
Report Question
0%
Alkali metals
0%
Alkaline earth metals
0%
Non - metals
0%
Noble gases
Explanation
According to Mendeleevs classification, the properties of elements are the periodic function of their atomic masses and there is a periodic recurrence of elements with similar physical and chemical properties. Noble gas being inert, could be placed in a separate group without disturbing the original order.
The three elements A, B and C with similar properties have atomic masses X, Y and Z respectively. The mass of Y is approximately equal to the average mass of X and Z. Such an arrangement of elements called as :
Report Question
0%
Dobereiner triad
0%
Mendeleev triad
0%
Newland triad
0%
None of the above.
Explanation
Dobereiner observed in a few atoms that the mass of one atom is equal to the average of two atoms. He defined almost all properties based on atomic weight. Hence, this is called Dobereiner triad.
Lithium has 7, sodium has 23 whereas potassium has 39 as atomic masses.
$$ 23 = (7+39)/2 = 23$$
Here, we could observe that atomic mass of sodium is the average of atomic masses of potassium and lithium.
Dobereiner grouped the elements into triads and Newland gave the:
Report Question
0%
Law of Octaves
0%
Law of multiple proportion
0%
Law of constant proportion
0%
None of these
Explanation
Newlands stated that, if the chemical elements are arranged according to increasing atomic weight
, those with similar physical and chemical properties occur after each interval of seven elements.
Newlands was one of the first to detect a periodic pattern in the properties of the elements and anticipated later developments of the periodic law. Hence called the law of octaves.
Which of the following is not a noble gas?
Report Question
0%
Helium
0%
Xenon
0%
Radium
0%
Radon
Explanation
Helium, xenon and radon are inert gases. Radium is an alkaline earth metal.
Statement: In Dobernier's classification of elements, the atomic mass of the middle element is equal to the average atomic masses of the extreme elements of a triad.
State whether the given statement is true or false.
Report Question
0%
True
0%
False
Explanation
Dobereiner classified the elements into triads (group of three). He made the groups such that the atomic mass of the middle element was the average atomic mass of the other two elements. This is Dobernier's law of triads.
$$Li$$, $$Na$$, $$K$$ is an example of Dobereiner's triad. Here, the average atomic mass of $$Li$$ and $$K$$ is equal to the atomic mass of $$Na$$
$$\frac{(7+39)}{2} = 23$$
Thus, given statement is true.
The number of valence electrons of caesium is:
Report Question
0%
1
0%
2
0%
6
0%
3
Explanation
As the atomic number of caesium is 55, its electronic configuration is 2, 8, 18, 18, 8, 1. This shows that the valence electrons of caesium is 1.
If the two members of a Dobereiner's triad are chlorine and iodine, then the third member of this triad is :
Report Question
0%
fluorine
0%
bromine
0%
sodium
0%
calcium
Explanation
According to Dobereiner, the atomic mass of the middle element is nearly equal to the arithmetic mean of the other two.
Therefore, the atomic mass of the third element is $$=$$ $$\dfrac{{35.5}+{127}}{2}$$ $$=$$ 81.25, which is the atomic mass of bromine.
Which of the following triads does not follow Dobereiner's law of triads?
Report Question
0%
Li, Na, K
0%
Ca, Sr, Ba
0%
Be, Mg, Ca
0%
Cu, Ag, Au
Explanation
Since the atomic weight of Ag is not equal to the mean of the atomic weights of Cu and Au.
Thus, (Cu, Ag, Au) triad do not follow Dobereiner's law of triads.
Option D is correct.
Which of the following elements has the least non-metallic character?
Report Question
0%
Fluorine
0%
Chlorine
0%
Bromine
0%
Iodine
Explanation
Non-metallic character increases from left to right in a period and decreases from top to bottom in a group. Thus, order of non-metallic character is F > Cl > Br > I.
The least non-metallic character will be in Iodine.
Mendeleev classified elements in:
Report Question
0%
increasing order of atomic groups.
0%
seven periods and eight groups.
0%
seven periods and nine groups
0%
eight periods and seven groups.
Explanation
Mendeleev kept elements in increasing order of atomic weights in seven periods and eight groups.
Therefore, option $$B$$ is correct.
Atomic number of an element isWhat is the nature of the element?
Report Question
0%
Alkali metal
0%
Transition metal
0%
Non metal
0%
Halogen
Explanation
Atomic number 16 have $$2,8,6$$ configuration and so to complete octet it needs two electron thus has tendency to accept electron.
Due to this electron accepting tendency, it is non-metal.
Which has more non-metallic character from the elements $$' X'$$ and $$' Y'$$, with electronic configurations $$2, 8, 5$$ and $$2, 8, 6$$ respectively?
Report Question
0%
$$X$$
0%
$$Y$$
0%
Both have same non-metallic character
0%
None of the above
Explanation
As we move from left to right across a period, the non-metallic character increases. Here, $$X$$ has atomic number $$15$$, so, the element is Phosphorous. $$Y$$ has atomic number $$16$$, so, the element is
Sulphur. As sulphur is present more to the right of the table, so according to the general trend it is more non-metallic.
So, $$Y$$ has
more non-metallic character.
Hence, option $$B$$ is correct.
Name the following with reference to the elements of the modern periodic table.
The alkali metal in period 2
Report Question
0%
H
0%
Li
0%
Rb
0%
Cs
Explanation
The group IA elements (Li, Na, K, Rb, Cs and Fr) are called alkali metals and the group II A elements (Be, Mg, Ca, Sr, Ba and Ra) are called alkaline earth metals.
According to this, period 2 alkali metal is Li.
The element with maximum non metallic character is:
Report Question
0%
$$S$$
0%
$$P$$
0%
$$Cl$$
0%
$$Ag$$
Explanation
As we move down the group, tendency to lose electron increases and metallic character increases while as we move across a period, electronegativity increases so non-metallic character increases.
So, among these $$Cl$$ have highest non-metallic character.
Hence, option C is correct.
The type of elements present in group 18[0] are :
Report Question
0%
alkali metals
0%
alkaline earth metals
0%
halogens
0%
noble gases
Explanation
Group 18 elements have complete octet except He and they are inert in nature so this group represents noble gases/inert gases.
$$K$$ has a larger atomic radius than $$Li$$. This confirms:
Report Question
0%
atomic radius decreases down a group.
0%
atomic radius increases down a group.
0%
atomic radius decreases across a period.
0%
atomic radius increases across a period.
Explanation
Atomic radius increases down a group. $$K$$ and $$Li$$ are in the same group, and $$K$$ lies below $$Li$$. $$K$$ has a larger atomic radius than $$Li$$. This happens because as we move down the group new shells are added and this increases the distance between the outermost electron and the nucleus.
Atomic weight of which set of elements were corrected by Mendeleev?
Report Question
0%
$$Li, Na, K$$
0%
$$U, Be, In$$
0%
$$Tc, Sc, Al$$
0%
None of the these
Explanation
Mendeleev corrected atomic weights of Uranium, Beryllium, and Indium ($$U, Be, In$$) based on their positions in the periodic table. Along with that h
e also corrected the atomic weights of Gold ($$Au$$) and Platinum ($$Pt$$).
Options $$B$$ is correct.
Which is not anomalous pair of elements in the Mendeleev's periodic table?
Report Question
0%
$$Ar$$ and $$K$$
0%
$$Co$$ and $$Ni$$
0%
$$Te$$ and $$I$$
0%
$$Al$$ and $$Si$$
Explanation
Anomalous pairs are those pairs of elements in which the increasing order of atomic masses was not obeyed. Mendeleev placed these elements according to a similarity in properties and not in the increasing order of their atomic mass.
(A) $$Ar$$ ( at mass = 39.9) is placed before $$K$$ (at mass = 39.1)
(B) $$Co$$ (at mass = 58.9) is placed before $$Ni$$ (at mass = 58.6)
(C) $$Te$$ (at mass = 127.6 ) is placed before $$I$$ (at mass = 126.9).
(D) $$Al$$ and $$Si$$ is not anomalous pair of elements in the Mendeleev's periodic table. $$Al$$ (at mass = 26.98) is placed before $$Si$$ (at mass = 28.4) means $$Al$$ and $$Si$$ are in increasing order of their atomic masses. Therefore they are not Anomalous pair.
The type of elements present in group 17 [VIIA] are :
Report Question
0%
alkali metals
0%
alkaline earth metals
0%
noble gases
0%
halogens
Explanation
Group 17 elements are called halogens, it includes F, Cl, Br, I and At.
The term atomic radius refers to?
Report Question
0%
Charge of the atom
0%
Size of the atom
0%
Distance between the centre of nucleus and the first shell
0%
Size of the outermost orbital
Explanation
The atomic radius refers to the size of an atom. It is the distance between the centre of the
nucleus and the outermost shell of an atom.
Atomic radius generally decreases on moving left to
right across a period and
increases down the group.
In which part of a group would you separately expect the elements to have
the greatest metallic character?
Report Question
0%
group 1
0%
group 2
0%
group 17
0%
group 18
Explanation
In group 1, we expect the elements to have greatest metallic character because if they donate 1 electron in their valence shell they get octet configuration and stability. Hence, they have huge tendency to donate electrons. Hence, group 1 has greatest metallic character.
Fill in the blanks with the appropriate words in each case
Element 'B' in period 2 is to the right of element 'A'.
Element 'B' is likely to be ____non-metallic in character than element 'A'
Report Question
0%
more
0%
less
0%
same
0%
none of these
Explanation
As we move across a period, metallic character decreases and non metallic character increases.
So, e
lement 'B' is likely to be more non-metallic in character than element 'A'.
In the periodic table, the metallic character of element :
Report Question
0%
decreases from left to right across a period and on descending a group
0%
decreases from left to right across a period and increases on descending a group
0%
increases from left to tight across a period and on descending a group
0%
increases from left to right across a period and decreases on descending a group
Explanation
In the periodic table, the metallic character of element decreases from left to right across a period and increases on descending a group. The same order is of the atomic radius. Reverse order is true for ionization energy, electron affinity and electronegativity.
The diagram represents an atom 'X'. Answer the following.
If atom 'X' has 1 electron in its outer shell, is it a non-metal.
Report Question
0%
True
0%
False
Explanation
Electronic dot structure
of Na (11): 2, 8 ,1.
It has a tendency to lose one electron to attain stability. Therefore, it is metal.
0:0:1
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
0
Answered
0
Not Answered
0
Not Visited
Correct : 0
Incorrect : 0
Report Question
×
What's an issue?
Question is wrong
Answer is wrong
Other Reason
Want to elaborate a bit more? (optional)
Practice Class 10 Chemistry Quiz Questions and Answers
<
>
Support mcqexams.com by disabling your adblocker.
×
Please disable the adBlock and continue.
Thank you.
Reload page
