Q8. Which one of the following equations correctly represents electron capture of ?

Background

Topic: Nuclear Chemistry – Radioactive Decay

This question tests your understanding of nuclear reactions, specifically electron capture, and how to write nuclear equations for isotopes undergoing this process.

Key Terms and Formulas:

• Electron Capture: A process in which an inner orbital electron is captured by the nucleus, combining with a proton to form a neutron.

• Nuclear Equation: Shows the reactants and products of a nuclear reaction, including atomic and mass numbers.

• Notation: , where is mass number, is atomic number, is element symbol.

• Electron: (sometimes written as for electron capture).

Step-by-Step Guidance

1. Recall that electron capture involves the nucleus absorbing an electron ( or ) from the atom's own electron cloud.

2. Write the reactants: the original nuclide () and the electron ().

3. Determine the product: electron capture converts a proton into a neutron, so the atomic number decreases by 1, but the mass number stays the same.

4. Set up the nuclear equation: ?

5. Identify the element with atomic number 20 and mass number 40 (from the periodic table).

Try solving on your own before revealing the answer!