In the formation of a compound AB, an atom of element A lost two electrons while an atom of element B gained two electrons. Predict two properties of AB.

Explanation

To determine the properties of the compound AB formed by the transfer of electrons between elements A and B, we can follow these steps:

### Step 1: Identify the Type of Bond
- In the formation of compound AB, atom A loses two electrons, and atom B gains two electrons. This transfer of electrons indicates that an ionic bond is formed between the two atoms.

### Step 2: Understand the Nature of Ionic Compounds
- Ionic compounds are typically formed between metals and non-metals. The metal (in this case, element A) loses electrons to become a positively charged ion (cation), while the non-metal (element B) gains electrons to become a negatively charged ion (anion).

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