Modern Periodic Law And The Present Form Of The Periodic Table

To solve this question, we need to determine the number of s-block and p-block elements in the second period of the modern periodic table.

1. Second Period of the Periodic Table:
The second period consists of 8 elements:
- The first two elements (Li and Be) are in the s-block.
- The last six elements (B, C, N, O, F, and Ne) are in the p-block.

2. Identifying s-block and p-block Elements:
- The s-block elements in the second period are: Lithium (Li) and Beryllium (Be). Hence, there are 2 s-block elements.
- The p-block elements in the second period are: Boron (B), Carbon (C), Nitrogen (N), Oxygen (O), Fluorine (F), and Neon (Ne). Hence, there are 6 p-block elements.

Final Answer:
Option (C) 2, 6 is correct.

To solve this problem, we need to identify the elements of group 2 (IIA) in the modern periodic table.

1. Group 2 (IIA) Elements:
In the modern periodic table, the elements in group 2 are known as alkaline earth metals. These elements include beryllium (Be), magnesium (Mg), calcium (Ca), and others. They are characterized by having two electrons in their outermost shell and typically exhibit basic (alkaline) properties when reacting with water.

2. Evaluating the Options:
(1) Alkali metals – Incorrect (Alkali metals are in group 1, not group 2.)
(2) Alkaline earth metals – Correct ✅ (Group 2 elements are called alkaline earth metals.)
(3) Halogens – Incorrect (Halogens are in group 17.)
(4) Noble gases – Incorrect (Noble gases are in group 18.)

Final Answer:
The correct option is (B) Alkaline earth metals.

To solve the problem, we need to identify the pair of atomic numbers that correspond to s-block elements.

1. Understanding the s-block Elements:
S-block elements are those elements whose outermost electrons are in the s-orbital. These elements are found in the first two groups of the periodic table (Group 1 and Group 2). The s-block elements include the alkali metals and alkaline earth metals.

2. Analyzing the Given Atomic Numbers:

• Atomic numbers 5 and 6 correspond to Boron (B) and Carbon (C), which are not s-block elements.
• Atomic numbers 9 and 10 correspond to Fluorine (F) and Neon (Ne), which are not s-block elements.
• Atomic numbers 11 and 12 correspond to Sodium (Na) and Magnesium (Mg), both of which are s-block elements.
• Atomic numbers 7 and 8 correspond to Nitrogen (N) and Oxygen (O), which are not s-block elements.

Final Answer:
The pair of atomic numbers that indicates the s-block elements is 11 and 12 (Option C).

To determine the total number of inner transition elements in the modern periodic table, we need to understand the structure and classification of the periodic table.

1. Understanding Inner Transition Elements:
Inner transition elements are a subset of transition metals located at the bottom of the periodic table. They are divided into two series:

• Lanthanides (or Lanthanoid Series): These elements occupy the 6th period and correspond to the filling of the 4f orbitals. The lanthanide series includes elements from cerium ( , atomic number 58) to lutetium ( , atomic number 71). This series contains 14 elements.
• Actinides (or Actinoid Series): These elements occupy the 7th period and correspond to the filling of the 5f orbitals. The actinide series includes elements from thorium ( , atomic number 90) to lawrencium ( , atomic number 103). This series also contains 14 elements.

2. Total Number of Inner Transition Elements:
The total number of inner transition elements is the sum of the elements in the lanthanide series and the actinide series:

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