Name two metal carbonates from which carbon dioxide cannot be prepared by heating.

Explanation

To answer the question, "Name two metal carbonates from which carbon dioxide cannot be prepared by heating," we can follow these steps:

### Step-by-Step Solution:

1. **Understand the Question**: The question is asking for two specific metal carbonates that do not release carbon dioxide (CO2) when heated.

2. **Identify Stable Metal Carbonates**: We need to recall which metal carbonates are stable and do not decompose upon heating. The carbonates of sodium (Na) and potassium (K) are known to be stable.

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