The atomic number of potassium is 19 and that of calcium is 20. If the 19th electron is removed from K, the energy required is $x \times 10^2$ kJ/mol. Find $x$ (IE₁ of K ≈ 419 kJ/mol).
Answer (integer)
42
Solution
IE₁ of K = 419 kJ/mol ≈ 42 × 10 kJ/mol. $419/10 = 41.9$, so $x ≈ 42$.
About this question
Subject: Chemistry · Chapter: s-Block Elements · Topic: Alkali Metals
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