Question

Four elements A, B, C, D have 1,2,6,7 valence electrons in their atoms. Assuming that they belong to the same period identify the strongest oxidizing agent among them:
A. A
B. B
C. C
D. D

Answer 1

Hint: To answer this question, you should recall the concept of oxidizing and reducing power and the factors that affect the given property. You should recall the trends in the periodic table. The atom which can gain electrons easily will be the strongest oxidizing agent.

Complete step by step answer:
The differences between oxidation and reduction are:

Oxidation involves	Reduction involves
Losing electrons	Gaining electrons
Increase in oxidation number	A decrease in oxidation number
For a given compound losing hydrogen	For a given compound gaining hydrogen

The element D with 7 valence electrons will have the strongest electron affinity to gain an electron so as to attain stable noble gas configuration. Thus, it readily gets reduced and is the strongest oxidising agent.

Hence, the correct answer to this question is option D.

Note:
Let us summarize the trends of fundamental properties of an element: Atomic Radii and Ionic radii: The atomic radii and ionic radii of elements decrease while moving from left to right in a period. Ionization Enthalpy: Across a period in the periodic table, ionization energy generally increases. For the trend in a group, ionization enthalpy decreases from top to bottom. Electron gain enthalpy: Electron gain enthalpy becomes more negative as we move from left to right in a period. Electron gain enthalpy is negative when energy is released while accepting an electron. While it is positive when energy is supplied to an atom while adding an electron.