Copper oxidizes in moist air
2Cu + CO₂ + O₂ + H₂O = (CuOH)₂CO₃
copper reacts with concentrated acids, for example, with nitric acid
Cu + 4HNO₃ = Cu(NO₃)₂ + 2NO₂ + 2H₂O
copper reacts with chlorine
Cu + Cl₂ = CuCl₂
copper reacts with oxygen when heated
2Cu + O₂ = 2CuO
7.30 x 10^-7 km. the others have 4 significant figures.
When an ionic is placed in water a dissolving reaction occurs so the positive or negative ion are only attracted to each other
The answer is (3) CH3COOH. CH3COOH is a acid. It can ionized in water. So the solution can conduct an electric current. And the other three can not be ionized in water.
The answer to this question I think would be 2: Better