Question 8.
Write down the electronic configuration of the following elements from the given atomic numbers. Answer the following question with explanation.
11Na, 15P, 17C1, 14Si, 12Mg
Which of these has largest atoms?
Answer:
Electronic configuration:
⇒ The atomic number of sodium = 11
The electronic configuration of 11Na = 2,8,2
⇒ The atomic number of phosphorus = 15
The electronic configuration of 15P = 2,8,5
⇒ The atomic number of chlorine = 17
The electronic configuration of 17Cl = 2,8,7
⇒ The atomic number of silicon = 14
The electronic configuration of 14Si = 2,8,4
⇒ The atomic number of magnesium = 12
The electronic configuration of 12Mg = 2,8,2
Among the given elements, Na is the element which has largest atoms.
Explanation:
All the given elements have total three shells present in them which means all the elements belong to the same period (period 3).
⇒ The atomic radius decreases as we move from left to right in a period.
⇒ Thus, Na has the largest atomic radius.
