Question

s-block element which cannot be qualitatively confirmed by the flame test is

• A. Li
• B. Na
• C. Rb
• D. Be

Answer 1

The Correct Option is D

To solve the question, we need to understand the flame test and its relevance to s-block elements in the periodic table.

The flame test is an analytical procedure used to detect the presence of certain metals based on the color of the flame they produce when heated. This test is commonly used for alkali and alkaline earth metals.

1. Li (Lithium): Lithium produces a crimson color in a flame test, which can be easily identified.
2. Na (Sodium): Sodium gives a bright yellow color in the flame test, which is very distinctive and easy to confirm.
3. Rb (Rubidium): Rubidium produces a reddish-violet color, which can be recognized although it might be less intense than lithium or sodium.
4. Be (Beryllium): Beryllium is unique among the listed elements as it does not emit a characteristic color in the flame test. Its compounds do not vaporize easily, preventing the release of electrons that would cause visible light emission. Thus, Beryllium cannot be qualitatively confirmed using the flame test.

Based on the analysis above, the correct answer is Be (Beryllium), as it cannot be detected or confirmed using the flame test.