Question

2. Give the number of the group and period of
the element having three Shells
Shells with three
electrons in valence shell.​

Answer 1

Answer: The group number is 13 and period is 3.

Explanation:  

An element which has three shells (it means that n = 3) with three electrons (it means that 3 valence electrons).  

The value of principle quantum number denotes the period in which an element belongs. Thus, this element belongs to Period 3.

The valence electrons of this element are 3. The last electron is entering p-sub-shell. Thus, it belongs to p-block. The group number for this element = Number of electrons + 10 = 3 + 10 = 13.  

Thus, this belongs to Group 13.

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