Answer:
The common element is Oxygen.
Explanation:
In order to find out the common elements between water, rust and carbon dioxide we will first write down the chemical formulas of these compounds.
(i) Water = H₂O
Each water molecule is made up of two atoms of hydrogen and one atom of oxygen.
(ii) Carbon Dioxide = CO₂
Carbon dioxide is made up of one atom of carbon and two atoms of oxygen.
(iii) Rust = Fe₂O₃
Rust is formed when Fe (Iron) is oxidized. Hence, it is made up of two iron atoms and three oxygen atoms.
Conclusion:
Hence, Oxygen is the only common element found in all these three compounds.
