Question

What happens when lead oxide is heated?

• A. Two compounds are formed.
• B. An element and a compound is formed.
• C. Two elements are formed.
• D. A compound is formed.

Answer 1

The correct option is C

Two elements are formed.

• When lead oxide is heated, it breaks into Lead (Pb) and Oxygen gas (O₂)
• An element is a pure substance which contains only one kind of atoms.
• A compound is a pure substance which contains two or more than two types of atoms in a fixed ratio by mass. Example: Lead oxide (PbO) is a compound as it consists of two types of atoms i.e. Lead and Oxygen.
• $$\begin{gathered} 2\mathrm{PbO}\left(\mathrm{s}\right)\stackrel{∆}{\to }2\mathrm{Pb}\left(\mathrm{s}\right)+{\mathrm{O}}_2\left(\mathrm{g}\right) \\ (\mathrm{Lead}\mathrm{oxide})\left(\mathrm{Lead}\right)\left(\mathrm{Oxygen}\right) \end{gathered}$$
• As Lead (Pb) and Oxygen (O₂) formed in the products consist of only one type of atoms, hence they are elements. So, two elements are formed when the lead oxide is heated.

Therefore, option (c) is correct.