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
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Gaps were left in between the periodic table
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Properties of elements were considered periodic function of their atomic masses
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Position of hydrogen in the periodic table
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Consideration of only 63 elements
C
Correct answer
Explanation
Hydrogen was not given fixed position in periodic table and worked in group I A and VII A. During Mendeleev’s time, only 63 elements were known.
C
Correct answer
Explanation
Calcium belongs to the fourth period and has 4 shells. All others belong to the third period and have 3 shells.
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Li < Be < C < N
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N < C < Be < Li
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Hi < Be < N < C
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C < N < Be < Hi
C
Correct answer
Explanation
C – 4, N – 3, Be – 2, Hi – 0
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Second period
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Third period
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Fourth period
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Fifth period
B
Correct answer
Explanation
Atomic number - 13 [2, 8, 3]
There are three shells, which correspond to the third period. So, the element will lie in the third period.
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They have the same atomic size.
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They have the same metallic character.
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They have the same number of valence electrons.
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They have the same number of electronic shells.
C
Correct answer
Explanation
Number of valence electrons remains the same in group.
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Be < Ca < Mg
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Be < Mg < Ca
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Ca < Mg < Be
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Mg < Ca < Be
B
Correct answer
Explanation
Atomic size increases on moving down the group.
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Electron
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Proton
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Neutron
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None of these
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Period 2
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Period 4
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Period 6
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Period 8
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B
Correct answer
Explanation
Period 4 elements contain 4 shells. Titanium atoms have 22 electrons and the shell structure is 2.8.10.2. As it contains 4 shells, so it belongs to the 4th period.
A
Correct answer
Explanation
An element belonging to group 4 will contain 4 electrons in the outermost shell and as it belongs to the 2nd period, it suggests that it contains 2 shells. Hence, the electronic configuration of this element would be 2,4 and the atomic number would be 6, i.e. carbon.
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2nd group
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3rd group
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5th group
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7th group
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B
Correct answer
Explanation
Mg is the correct chemical symbol for Magnesium. Chemical symbols are standardized internationally - Mg comes from the Latin 'Magnesium'. Option A (Ma) is incorrect, Mn is Manganese, and the 'None of these' option is unnecessary since the correct answer is present.
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Group V of periodic table
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Group VI of periodic table
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Group VII of periodic table
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Group VIII of periodic table
D
Correct answer
Explanation
Noble gases (helium, neon, argon, krypton, xenon, radon) are placed in Group 18 of the modern periodic table, which was historically designated as Group VIII. These elements have complete valence electron shells, making them extremely unreactive.
A
Correct answer
Explanation
The chemical symbol for aluminum is 'Al', derived from its Latin name 'alumen'. Gold is 'Au', and single-letter symbols are not used for aluminum in the periodic table.
B
Correct answer
Explanation
The chemical symbol for hydrogen is 'H', derived from its Latin name 'Hydrogenium'. 'Hy' would be incorrect as chemical symbols use either one or two letters (first letter capitalized, second lowercase). 'Hn' is not a standard chemical symbol for any element.
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glass : thermometer
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hydrogen: air
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atmosphere : oxygen
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graphite : granite
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pyrite : fool's gold
E
Correct answer
Explanation
Mercury is commonly referred to as quicksilver. Pyrite is commonly referred to as fool's gold.