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

The electrons which are present in the outer shell are

  1. valence electrons

  2. bond electrons

  3. excited electrons

  4. None of these
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Valence electrons are electrons in one of the outer shells of an atom that can participate in forming chemical bonds with other atoms.

Multiple choice

Which is the symbol of ' Phosphorous' element?

  1. Ph

  2. P

  3. Po

  4. None of these
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

The chemical symbol for Phosphorus is 'P', derived from its Latin name 'Phosphorus'. 'Ph' is not a valid element symbol, and 'Po' is Polonium.

Multiple choice

The best position of hydrogen in the periodic table is above IA group. What is the reason?

In the classification of elements in the periodic table, hydrogen is placed at the top of IA group. It has many similarities with the group elements.

  1. Electropositive nature of all the IA group elements

  2. All the elements have similar outermost shell configuration

  3. Elements have the tendency to form ionic compouds.

  4. All the elements have low melting points.

  5. All of the above
Reveal answer Fill a bubble to check yourself
E Correct answer
Explanation

All the answers given above are correct.

Multiple choice

Hydrogen resembles with carbon because of

1H1- hydrogen belongs to first group of periodic table with the electronic configuration of 1s1.

6C12- carbon belongs to p-block and electronic configuration is 1s22s22p4.

  1. the same number of electrons in the valence shell

  2. similar physical properties

  3. remarkable reducing properties

  4. homovalent similarity

  5. allotropy similarity
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Reduction is a chemical reaction in which proton is added or electron is removed.

Reduction is a chemical reaction in which proton is added or electron is removed.
Multiple choice

Five elements A, B, C, D and E have the following atomic numbers. Among these elements, which element belongs to third period and has the highest ionisation potential?

The minimum amount  of energy is required to pull out an electron from an atom or molecule in the gaseous state.
The first ionisation energy is the energy required to remove the most loosely held electron from one mole of gaseous atoms to produce 1 mole of gaseous ions, each with a charge of 1+.

X(g)------------>X++e-
It is the energy needed to carry out this change per mole of X.

  1. A = 12

  2. B = 17

  3. C = 18

  4. D = 7

  5. E = 11
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

The element C is argon.

Multiple choice

Which of the following does not increase while moving towards higher groups?

Periodic properties of chemical elements reoccur periodically. This is the basis of creation of periodic table. In the classification of elements, elements show a periodic trend in many properties. The main basis of classification of these elements is increasing atomic number, which represents increasing positive charge in the nucleus. Negatively charged electrons are arranged in orbitals around the nucleus. The recurring properties of these elements are due to recurring configurations of these electrons in the orbitals around the nucleus.

  1. Atomic radius

  2. Metallic character

  3. Valency

  4. Electronegativity

  5. Ionisation energy
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

In a group, valency is always constant. Across a period, it always increases.

Multiple choice

The element which has zero electron affinity in the third period is

When an electron is added to a neutral atom in the gaseous state, certain amount of energy is released. During this process, this energy is called electron affinity of that particular atom.

 X + e-----> X -

For explanation to this question, first electronic configurations of all these elements have to be taken into consideration.

  1. 13Al26

  2. 15P30

  3. 18Ar39

  4. 14Si28

  5. 16S32
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Electronic configuration = 1s22s22p63s23p6   Electron affinity value = 0 The outermost shell is completely filled, therefore the electron affinity value is zero.