List of top Science and Technology Questions on Periodic Classification of Elements

Choose the correct alternative:
Alkaline earth metals have valency 2. This means that their position in the modern periodic table is in .................... .
Write the electronic configuration of chlorine.
What is the number of electrons in the valence shell of chlorine?
The atom having smallest atomic mass.
The noble gas with the smallest atomic radius.
The most electronegative atom.
While going from left to right within a period, the size of the atom decreases.

एका मूलद्रव्याची इलेक्ट्रॉन संरचना 2, 8, 1 अशी आहे. त्यावरून खालील प्रश्नांची उत्तरे लिहा : 
(अ) या मूलद्रव्याचा अणुक्रमांक किती ? 
(ब) या मूलद्रव्याचा गण कोणता ? 
(क) हे मूलद्रव्य कोणत्या आवर्तात आहे ? 
 

शास्त्रीय कारणे लिहा (कोणतीही तीन) : 

एका गणसमूहातील मूलद्रव्यांची संयुजता समान असते. 
 

An element has its electron configuration as \(2, 8, 1\). Now answer the following questions: 

  1. What is the atomic number of this element? 
  2. What is the group of this element? 
  3. To which period does the element belong? 
Define periods and groups of the modern periodic table.
Elements belonging to the same group have the same valency.