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Structure of the Atom — Science STD 9 — Question

CBSE BoardEnglish MediumSTD 9ScienceStructure of the Atom5 Marks
Question
The atom of an element X has 7 electrons in its M shell:
  1. Write the electronic configuration of element X.
  2. What is the atomic number of element X?
  3. Is it a metal or a non-metal?
  4. What type of ion will be formed by an atom of element X? Write the symbol of the ion formed.
  5. 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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