Question 1

What is the basic theme of organization in the periodic table?

Accepted Answer

The basic theme of organisation in the periodic table is to characterise the elements in periods and groups as per their properties. This arrangement simplifies and systematises the study of elements and their compounds. Elements with comparative properties are placed in the same group.

Question 2

Which vital property did Mendeleev use to order the elements in the periodic table that he designed and did he adhere to that?

Accepted Answer

Mendeleev organised elements in his periodic table according to the order of their atomic weight, arranging them in groups and periods based on increasing atomic weight. However, he did not adhere to this arrangement for long. He found that if elements were organised solely by increasing atomic weights, some elements did not fit within his classification plan. Therefore, he occasionally overlooked the order of atomic weights. For example, despite iodine having a lower atomic mass than tellurium,

Question 3

State difference between Mendeleev’s Approach for periodic law and the Modern approach for the periodic law.

Accepted Answer

Mendeleev’s Approach for periodic law: Chemical and physical properties of elements are periodic functions of the atomic mass of the corresponding elements.  Modern approach for the periodic law: Chemical and physical properties of elements are periodic functions of the atomic numbers of the corresponding elements.

Question 4

On the premise of the quantum numbers, verify that the 6th period of periodic table ought to have 32 components.

Accepted Answer

In a periodic table, a period indicates the value of the principal quantum number (n) for the outermost shells. Each period starts with the filling of the principal quantum number (n). For the 6th period, n = 6. For n = 6, the azimuthal quantum number (l) can have values of 0, 1, 2, 3, 4. According to Aufbau’s rule, electrons are added to various orbitals according to their increasing energies. In this case, the 6d subshell has much higher energy than the 7s subshell.  In the sixth period, elect

Question 5

In groups and periods of periodic table where will you find the elements which is having Z =114?

Accepted Answer

Elements with atomic numbers from Z = 87 to Z = 114 are found in the seventh period of the periodic table. Therefore, the element with Z = 114 is in the seventh period.  In the seventh period: The initial 2 elements (Z = 87 and Z = 88) are s-block elements. The following 14 elements (except Z = 89, i.e., Z = 90 to Z = 103) are f-block elements. The next 10 elements (Z = 89 and Z = 104 to Z = 112) are d-block elements. The elements from Z = 113 to Z = 118 are p-block elements.  Thus, the element

Question 6

What is the atomic number of element keeping in mind both the cases given below;
1. Element is in 3rd period of periodic table.
2. Element is in 17th group of periodic table.

Accepted Answer

The first period has 2 elements, and the second period has 8 elements. So, the third period begins with element Z = 11. The third period contains 8 elements, with the 18th element being the last element of this period, located in the 18th group. Therefore, the element in the seventeenth group of the 3rd period has an atomic number of 17 (Z = 17).

Question 7

Which element are named by
a) Seaborg’s group
b) Lawrence Berkeley Laboratory?

Accepted Answer

a) The element named by Seaborg’s group is Seaborgium (Sg), which has atomic number, Z = 106. b) The elements named by Lawrence Berkeley Laboratory are Lawrencium (Lr), which has atomic number, Z = 103, and Berkelium (Bk), which has atomic number, Z = 97.

Question 8

Elements present in the same group are having similar chemical and physical properties. Why is it so?

Accepted Answer

The chemical and physical properties of any elements depend on the quantity of valence electrons. Elements in the same group in the periodic table have the same quantity of valence electrons. This is why elements present in the same group have similar chemical and physical properties.

Question 9

What do you understand by the term ‘Ionic radius’ and ‘atomic radius’?

Accepted Answer

Atomic radius: This is the radius of an atom, which quantifies its size. If the element is a metal, its radius is termed metallic radius. If it's a non-metal, its radius is termed covalent radius. Metallic radius can be calculated as half the inter-nuclear distance between two adjacent metal atoms in a solid. For instance, for solid copper, if the inter-nuclear distance is 256 pm, the metallic radius of copper is 256/2 pm = 128 pm. Covalent radius is measured as half the interatomic distance bet

Question 10

Explain why there is variation in atomic radius in a group and period?

Accepted Answer

Across a period (left to right): Atomic radius declines as we move from left to right in a period. This occurs because, in a period, the outermost electrons are in the same valence shell, but the atomic number increases from left to right. This increase in atomic number results in an increase in the effective nuclear charge. Therefore, the attraction of electrons towards the nucleus is increased, pulling the electrons closer.  Down a group (top to bottom): Atomic radius increases as we move down

Classification of Elements and Periodicity in Properties