All alkali metals will displace ….A…from cold water here A refers to

Options

A. oxygen
B. hydrogen
C. water
D. metals

Answer

**Step-by-Step Solution:**

1. **Understanding Alkali Metals:**
- Alkali metals are found in Group 1 of the periodic table. This group includes lithium (Li), sodium (Na), potassium (K), rubidium (Rb), cesium (Cs), and francium (Fr).
- They are known for their high reactivity, especially with water.

2. **Reactivity with Water:**
- When alkali metals react with water, they form hydroxides and release hydrogen gas.
- The general reaction can be represented as:
\[ \text{2M + 2H}_2\text{O} \rightarrow \text{2MOH + H}_2 \]
where M represents an alkali metal.

3. **Displacement Reaction:**
- In the context of the question, the term "displace" refers to the ability of alkali metals to replace another element in a compound or solution.
- When alkali metals react with cold water, they displace hydrogen from the water.

4. **Conclusion:**
- Therefore, the answer to the question is that all alkali metals will displace **hydrogen** from cold water.

**Final Answer:**
All alkali metals will displace **hydrogen** from cold water.

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