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

Multiple choice chemistry the periodic table newland's law of octaves development of the modern periodic table into the history

Which of the following pairs of elements do not follow octave rule?

  1. $Be, B$
  2. $Ca, Sr$
  3. $F, Cl$
  4. $O, S$
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

The octet rule in chemistry refers to the tendency of atoms to prefer to have eight electrons in the valence shell. Beryllium (Be) and Boron (B) are electron-deficient elements that often form compounds with fewer than eight valence electrons, thus failing to follow the octet rule.

Multiple choice chemistry the periodic table newland's law of octaves development of the modern periodic table into the history

The Newland's law of octaves for the classification of elements was found to be applicable only up to the element ______________________.

  1. potassium

  2. calcium

  3. cobalt

  4. phosphorous
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

The Newland's law of octaves for the classification of elements was found to be applicable only up to the element calcium.


Law of octaves, in chemistry, the generalization made by the English chemist J.A.R. Newlands in 1865 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.

Multiple choice chemistry the periodic table newland's law of octaves development of the modern periodic table into the history

John Newlands arranged the known elements in a/an  ______ order of their atomic _______ .

  1. increasing, masses

  2. decreasing, masses

  3. increasing, numbers

  4. decreasing, numbers
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

John Newlands arranged the known elements in an increasing order of their atomic masses. He started with the element having the lowest atomic mass ( hydrogen ) and ended at thorium which was the $56^{th}$ element. Some of the elements satisfying this order are arranged as $H, Li, Be, B, C, N, O$.

Multiple choice chemistry the periodic table newland's law of octaves development of the modern periodic table into the history
The given arranged sequence on the basis of their increasing atomic masses represents which law of classification of elements?  

$F, Na, Mg, Al, Si, P, S, Cl$ & $K$

  1. Modern table

  2. Newton's law

  3. Newland's law of octaves

  4. Mendeleev's periodic table
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Elements have been arranged in the following sequence on the basis of their increasing atomic masses.

    $F, Na, Mg, Al, Si, P, S, Cl$ & $K$

Law of octaves is given by the English chemist J.A.R. Newlands in 1865.
It states that if chemical elements are arranged according to increasing atomic weight, similar physical and chemical properties occur after each interval of seven elements.

Newlands was the first to detect a periodic pattern in the properties of the elements and anticipated later developments of the periodic law.

Multiple choice chemistry atoms, molecules and radicals history of atomic model atomic theory of dalton daltons atomic theory

Dalton said that elements are distinguished from each other by :

  1. the charge on their ions

  2. the density of their solid forms

  3. the weights of their atoms

  4. the shapes of their atoms
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Atoms of a given element are identical in size, mass and other properties, while atoms of different elements differ in size, mass and other properties.

Multiple choice chemistry atoms, molecules and radicals history of atomic model atomic theory of dalton daltons atomic theory

Atoms of different elements combine in :

  1. unequal ratios.

  2. prime number ratios.

  3. equal ratios.

  4. whole number ratios.
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

When elements react, their atoms combine in simple, whole-number ratios.   By suggesting that compounds contained characteristic atom-to-atom ratios, Dalton effectively explained the law of definite proportions.

Multiple choice physics nuclei gamma decay change in nucleus due to radioactive decay alpha, beta and gamma particles (rays) and their properties

When writing electron configurations,electrons are represented in their lowest possible energy state.Which of the following state is this ?

  1. excited state.

  2. lowest state.

  3. configuration state.

  4. ground state.

  5. unenergetic state.
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

According to Aufbau's principle, electrons are filled in the atomic orbitals in order of lower energy to the higher energy starting from the orbital of lowest possible energy known as the ground state.

Multiple choice chemistry structure of the atom electronic configuration and valency electron configuration periodic trends in physical properties

An atom of each element has a definite combining capacity called : 

  1. valency

  2. affinity

  3. bonding

  4. energy levels
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

An atom of each element has a definite combining capacity called its valency.

For example Na has electronic configuration 2,8,1 
So, valency is 1 as after losing one electron it will have stable octet.

Multiple choice chemistry the periodic table periodic trends in chemical properties alkali metals study of specific groups

Group contains the noble gases is_______ group.

  1. 16th

  2. 17th

  3. 18th

  4. Both B and C
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Group 18 contains noble gases.


They have already stable and octet configuration that is they contain 8 electrons in their outer most shell.

Hence they have high ionization potential and zero electron affinity.

They do not participate in chemical bonding because already they are stable.

Option C is correct.