Metal sol is negatively charged. True/False

Answer

To determine whether the statement "Metal sol is negatively charged" is true or false, we can analyze the properties of metal sols and their behavior in terms of charge.

### Step-by-Step Solution:

1. **Understanding Metal Sols**:
- Metal sols are colloidal solutions where metal particles are dispersed in a liquid. These metal particles can be formed from metals like arsenic, gold, silver, etc.

2. **Electron Donation by Metals**:
- Metals are known to be good electron donors. When a metal atom donates electrons, it becomes positively charged. For example, if a metal atom loses one or more electrons, it will acquire a positive charge.

3. **Formation of Metal Sols**:
- When metal ions are dispersed in a colloidal solution, they can ionize. For instance, if we take arsenic sulfide (As2S3), it can dissociate into arsenic ions (As3+) and sulfide ions (S2-).

4. **Charge of the Metal Sol**:
- In the case of metal sols, while the metal ions themselves are positively charged, the negatively charged ions (like S2-) can adsorb onto the surface of the metal particles. This adsorption of negatively charged ions leads to the overall charge of the sol being negative.

5. **Example of Ferric Hydroxide**:
- Another example is ferric hydroxide (Fe(OH)3), which dissociates into ferric ions (Fe3+) and hydroxide ions (OH-). The hydroxide ions, which are negatively charged, can also adsorb onto the surface of the ferric hydroxide particles, contributing to a net negative charge.

6. **Conclusion**:
- Based on the behavior of metal sols and the adsorption of negatively charged ions, we can conclude that the statement "Metal sol is negatively charged" is **True**.

### Final Answer:
**True** - Metal sol is negatively charged.