Alkali metlas are characterised by

Options

A. Good conductor of heat and electricity
B. High oxidation potentials
C. Low melting points
D. Solubility in liquid ammonia

Answer

To answer the question "Alkali metals are characterized by", we will analyze the characteristics of alkali metals based on the provided options.

### Step-by-Step Solution:

1. **Good Conductors of Heat and Electricity**:
- Alkali metals are known to be good conductors of heat and electricity. This is because they have one valence electron that can move freely within their structure, allowing for the conduction of electricity and heat.
- **Conclusion**: This characteristic is true for alkali metals.

2. **High Oxidation Potential**:
- Alkali metals have a high oxidation potential. This is due to their electronic configuration, which is of the form ns¹ (where n is the principal quantum number). They can easily lose their single valence electron to achieve a stable electronic configuration similar to that of noble gases (inert gases).
- **Conclusion**: This characteristic is also true for alkali metals.

3. **Lowest Melting Point**:
- While alkali metals do have relatively low melting points compared to many other metals, it is not accurate to say they are characterized by the lowest melting point among all elements. The melting points increase down the group but remain low compared to other metals.
- **Conclusion**: This characteristic is not a defining feature of alkali metals.

4. **Solubility in Liquid Ammonia**:
- Alkali metals are soluble in liquid ammonia, forming blue solutions. This is a unique characteristic of alkali metals, as they can dissolve in ammonia and exhibit distinctive properties in that solution.
- **Conclusion**: This characteristic is true for alkali metals.

### Final Answer:
Based on the analysis, alkali metals are characterized by:
- A) Good conductors of heat and electricity (True)
- B) High oxidation potential (True)
- C) Lowest melting point (Not a defining characteristic)
- D) Solubility in liquid ammonia (True)

Therefore, the correct options are A, B, and D.

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