Assertion : Be gives characteristic flame colouration.
Reason : Ionization energy of Be is high.

Options

A. Assertion and reason both are correct statements and reason is correct explanation for assertion.
B. Assertion and reason both are correct statements but reason is not correct explanation for assertion.
C. Assertion is correct statement but reason is wrong statement.
D. Assertion is wrong statement but reason is correct statement

Answer

To analyze the assertion and reason provided in the question, we will break down each part step by step.

### Step 1: Understand the Assertion
- **Assertion**: "Be gives characteristic flame colouration."
- Beryllium (Be) is an alkaline earth metal that is expected to show a characteristic flame color when heated. However, this is not the case.

### Step 2: Understand the Reason
- **Reason**: "Ionization energy of Be is high."
- Ionization energy refers to the energy required to remove an electron from an atom. Beryllium has a high ionization energy because it is the smallest atom in its group, and its outer electrons are held tightly by the nucleus.

### Step 3: Analyze the Assertion
- Beryllium does not produce a characteristic flame color when subjected to flame tests. This is because its high ionization energy makes it difficult to excite its electrons to higher energy levels, which is necessary for producing flame colors.

### Step 4: Analyze the Reason
- The reason given is correct; beryllium does have a high ionization energy. However, this high ionization energy is the reason why beryllium does not show characteristic flame coloration, not the other way around.

### Step 5: Conclusion
- Since the assertion is incorrect (Be does not give characteristic flame coloration), but the reason is correct (the ionization energy of Be is high), we conclude that:
- **Assertion**: False
- **Reason**: True

### Final Answer
- The correct option is that the assertion is false, but the reason is true.

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