Question

Suppose we have 12 protons and 12 neutrons. We can assemble them to form either a 24Mg nucleus or two 12C nuclei. In which of the two cases more energy will be liberated?

Answer 1

Answer:

For 24 Mg, more energy will be liberated.

Explanation:

To form 24 Mg, 12 electrons are to be added. Due to such addition, a full-filled electronic configuration will be formed (Mg: 1s-2 2s-2 2p-6 3s-2)

But to form one 12 C, 6 electrons are required and a incompletely filled valence shell orbital is formed (1s-2 2s-2 2p-4).

We know, filled orbitals are more stable than incompletely filled ones. So, more energy will be liberated to form 24 Mg than two 12 C nuclei.

Answer 2

Explanation:

• 92.15 MeV of energy is released when we try to assemble 6 neutrons and 6 protons to form 12C nucleus. 92.15 MeV is formed as it is the product of binding energy per nucleon of carbon-12 and the mass number.
• So, in the creation of two carbon nuclei, the released energy is 184.3 MeV.  
• In other terms, when 12 neutrons and 12 protons are united to form a 24Mg atom, there will be a release of 198.25 MeV of energy, which is a binding energy.
• So, there will be the liberation of more energy in case of 24Mg nucleus.