Question

Elements exhibiting the property of radioactivity have:

• A. stable nucleus
• B. stable electronic configuration
• C. unstable nucleus
• D. unstable electronic configuration

Answer 1

The correct option is C unstable nucleus

Elements with high atomic number such as uranium, thorium, radium exhibit the property of radioactivity. Since the atomic number of these elements are high, the number of protons in their nucleus is more. So their nucleus have more repulsion between likely charged protons. Hence, their nucleus is unstable. During radioactivity this unstable nucleus splits to form stable nucleus.