Chemistry
Periodic Classification and Elements
1,176 Questions
Periodic classification organizes chemical elements based on atomic structure, periodic laws, and elemental properties. It covers historical classification systems, electron configurations, and periodic trends. Test takers preparing for chemistry sections will find these questions crucial for mastering fundamental element properties and atomic interactions.
Periodic table structureAtomic orbitalsElement identificationPeriodic laws
Periodic Classification and Elements Questions
A
Correct answer
Explanation
Elements belonging to the 18th group of the periodic table have fully filled last valence shell. So, they have zero valency.
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It could classify eight elements.
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It consists of eight groups.
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Every eighth element has properties similar to the first.
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The classification was based on the atomic masses of elements.
C
Correct answer
Explanation
Newlands found that the properties of the eighth element were similar to the properties of the first element. He compared this with the octaves found in the musical scale. Therefore, this method of classification of elements is called Newlands’ Law of Octaves.
C
Correct answer
Explanation
In Mendeleev’s periodic table, there are 8 groups, which are further subdivided into 2 parts (e.g. I A, I B) and 7 periods.
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h / square root (2 ) π .
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0 .
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square root [ 6 ] h / 2π .
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square root [ 3 ] h / 2 π .
A
Correct answer
Explanation
This option is correct because L value of ' p ' orbital is 1 . Hence, this option is correct .
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spherical .
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Dumb- bell .
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Double dumb - bell .
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more complicated .
B
Correct answer
Explanation
this option is correct because , ' p ' orbital shows this shape whose l value is = 1 . hence this option is correct .
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n = 4 , l = 0 , m = 0 , s = + 1/ 2 .
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n = 3 , l = 0 , m = 0 , s = + 1/ 2 .
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n = 3 , l = 1 , m = 1 , s = + 1/ 2 .
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n = 3 , l = 2 , m = 1 , s = + 1/ 2 .
D
Correct answer
Explanation
this option is incorrect because , according to n+l rule , highest energy is possesed by that set which has highest value of n + l . so , in this case , n = 3 , l = 2 . hence n+l = 5 . which is not the highest among the options . hence this option is incorrect .
A
Correct answer
Explanation
this option is correct because , each value of m implies 1 orbital and each orbital can only accommodate 2 electrons . hence this option is correct .
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lithium .
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beryllium .
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hydrogen .
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boron .
A
Correct answer
Explanation
this option is correct because , lithium has electronic configuration - 1s2 2s1 . hence according to the question n = 2 means principle quantum number is 2 . l =0 means ' s ' orbital . s = + 1 / 2 means 1 electrons . all these characters are exhibited by lithium . therefore this option is correct .
A
Correct answer
Explanation
this option is correct because , for every value of ' m ' only one orbital exist . hence this option is correct .
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1s2 2s2 2p6 .
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1s2 2s2 2p7 .
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1s2 2s2 .
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1s2 2s2 2p5 .
B
Correct answer
Explanation
this option is correct because , p subshell has 3 orbital each can accommodate 2 electrons hence ' p ' orbital can accommodate 6 electrons . in this case p has 7 electrons . hence this statement is wrong and therefore this option is correct .
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principal quantum number .
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orbital quantum number .
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magnetic quantum number .
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spin quantum number .
D
Correct answer
Explanation
this option is correct because , according to pauli exclusion principal - no two electrons in an atom can have same sets of 4 quantum number . this shows that no 2 electrons in an atom are alike or orbital can be accommodate a maximum of two electrons that too with opposite spin . hence this option is correct .
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n= 4 , l = 3 , m = 2 , s = +1 / 2 .
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n= 4 , l = 2 , m = 1 , s = 0 .
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n= 4 , l = 3 , m = - 2 , s = +1 / 2 .
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n= 4 , l = 2 , m = 1 , s = +1 / 2 .
D
Correct answer
Explanation
this option is correct because , l value 2 is shown by ' d ' orbital . this configuration represent an electron in 4d orbital . hence this option is correct .
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s < p < d < f .
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s < p > d < f .
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s > p > d > f .
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s = p = d = f .
A
Correct answer
Explanation
This option is correct because , from n + l rule . higher the value of this term higher is the energy . Now n value is 4 in this case . and l values are in the order of s ( 0 ) < p ( 1 ) < d ( 2 ) < f ( 3 ) . Therefore, the correct order is s < p < d < f . Hence, this option is correct .
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shape of the orbital .
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subshell .
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Main energy shell of electron .
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spin of electrons .
C
Correct answer
Explanation
this option is correct because , energy is given by , E = -(13.6 Z2 ) / n2 . hence energy is dependent on principal quantum number . hence this option is correct .
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one node .
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two nodes .
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three nodes .
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four nodes .
C
Correct answer
Explanation
This option is correct becausI radial node = n - l -1 . planar node = l . total nodes = n - 1 . in this case n = 4, hence, total number nodes = 3 .