If in a reaction, copper (Cu) is reduced; its number of electrons has: Increased Remained Constant Maybe changed...depends on external factors Like anyone could really know this. I should ask Siri

## Step 1<br />In a chemical reaction, reduction refers to the process where an atom, ion, or molecule gains electrons. This process is always accompanied by an increase in the number of electrons.<br /><br />## Step 2<br />In the case of copper (Cu), when it is reduced, it means that it gains electrons. This process increases the number of electrons in copper.<br /><br />## Step 3<br />The number of electrons in an atom is a fundamental property and does not remain constant or depend on external factors. Therefore, the number of electrons in copper increases when it is reduced.