MCQ Detailed View

In the periodic table of elements, the vertical columns are known as Groups. Each group consists of elements that share similar chemical and physical properties because they have the same number of valence electrons in their outer shell.

There are 18 groups in the modern periodic table. They are numbered from 1 to 18, starting from the leftmost column (alkali metals) to the rightmost column (noble gases). For example:

• 
  

  Group 1 contains alkali metals like lithium (Li), sodium (Na), and potassium (K).

  
  


• 
  

  Group 17 contains halogens such as fluorine (F) and chlorine (Cl).

  
  


• 
  

  Group 18 contains noble gases like helium (He), neon (Ne), and argon (Ar).

  
  

The group number helps predict how an element will behave chemically. Elements in the same group typically form similar compounds and react in comparable ways. For instance, all alkali metals in Group 1 react with water to form alkaline solutions and release hydrogen gas.

Let’s review the incorrect options:

• 
  

  Periods: These are horizontal rows in the periodic table, not columns.

  
  


• 
  

  Rows: This is a general term but in periodic table terminology, they are called periods.

  
  


• 
  

  Lanthanoids series: This refers to a specific group of 15 elements placed separately at the bottom of the table, not a vertical column.

  
  

Understanding groups is essential in chemistry because it helps in classifying elements based on recurring chemical trends. The periodic table is designed to reflect these trends clearly, and groups play a key role in that organization.

So, the correct answer is B. Groups.

—