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Atoms and Molecules — Science STD 9 — Question

CBSE BoardEnglish MediumSTD 9ScienceAtoms and Molecules3 Marks
Question
An element A forms an oxide A2O5.
  1. What is the valency of element A?
  2. What will be the formula of chloride of A?
✓

Answer

  1. Element A forms an oxide A2O5. Crossing the valencies, we can see that the valency of O(oxide) is -2 and that of element A is 5.

  2. Formula of chloride of A:

$\text{Element/ Ion}\ \ \ \ \ \ \ \text{A}\ \ \ \ \ \ \text{Cl}^-\\ \ \ \ \text{Valency}\ \ \ \ \ \ \ \ \ \ \ \ \ \ 5\ \ \ \ -1$

Formula of the chlcride of element A can be worked out by crossing over the valencies. Thus, the formula is ACl5

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