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Structure of the Atom — Science STD 9 — Question

Maharashtra BoardEnglish MediumSTD 9ScienceStructure of the Atom5 Marks
Question
The atom of an element $X$ has $7$ electrons in its $M$ shell:
a. Write the electronic configuration of element X .
b. What is the atomic number of element $X$ ?
c. Is it a metal or a non-metal?
d. What type of ion will be formed by an atom of element $X$ ? Write the symbol of the ion formed.
e. What could element $X$ be?
✓

Answer

  1. Electronic configuration of the element $X$ is,
Element X: $\text{K}\ \ \ \ \ \ \text{L}\ \ \ \ \ \ \text{M}\\2\ \ \ \ \ \ \ 8\ \ \ \ \ \ \ 7$
  1. Atomic number of the element $X$ will be $17$
  2. Element $X$ is a non-metal because there are $7$ electrons in its outermost orbit. In order to complete its octet (to get $8$ electrons), it will gain one electron. An element which gains electrons in order to complete its octet is a non-metal.
  3. The element will form an anion by gaining an extra electron in order to complete its octet. Symbol of an ion of $X$ will be $X^-$
  4. $X$ is Chlorine.

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