57: 25 لَقَدْ أَرْسَلْنَا رُسُلَنَا بِالْبَيِّنَاتِ وَأَنزَلْنَا مَعَهُمُ الْكِتَابَ وَالْمِيزَانَ لِيَقُومَ النَّاسُ بِالْقِسْطِ ۖ وَأَنزَلْنَا الْحَدِيدَ فِيهِ بَأْسٌ شَدِيدٌ وَمَنَافِعُ لِلنَّاسِ وَلِيَعْلَمَ اللَّهُ مَن يَنصُرُهُ وَرُسُلَهُ بِالْغَيْبِ ۚ إِنَّ اللَّهَ قَوِيٌّ عَزِيزٌ
“We sent our messengers with clear signs and sent down with them the Book and the balance (of right and wrong), that people may stand forth in justice; and We sent down the iron, in which is great power, as well as benefits for mankind, that Allah may test who it is that will help, unseen, Him and His Messengers, for Allah is powerful, exalted in might.”
The above Ayat 25 of Sura 57, Al-Hadeed, mentions the great power of Iron. In terms of nuclear binding energy, Iron and Nickel together called the ‘iron group’ has the highest nuclear binding energy of all the elements of the periodic table. Nuclear binding energy is the energy that would be required to disassemble the nucleus of an atom into its component parts. These component parts are neutrons and protons, which are collectively called nucleons. The binding energy of nuclei is due to the attractive forces that hold these nucleons together. since most nuclei would require the expenditure of energy to separate them into individual protons and neutrons.
If new binding energy is available when light nuclei fuse, or when heavy nuclei split, either process can result in release of this binding energy. This energy may be made available as nuclear energy and can be used to produce electricity as in (nuclear power) or in a nuclear weapon. The nuclear binding energies and forces are on the order of a million times greater than the electron binding energies of light atoms like hydrogen.
The stability of a nucleus is determined by how much Nuclear binding energy it has per nucleon (proton or neutron). The more binding energy in a nucleus, the harder it is to split it apart.
Iron is a “special” element because of its nuclear binding energy. The very basic idea is that when you fuse two light elements together, you get a heavier element plus energy. You can do this up to iron. Similarly, if you have a heavy element that undergoes fission and splits into two lighter elements, you also release energy, down to iron. Iron is just in the middle of graph of heavier and lighter elements.
Interestingly, the Sura no. Al-Hadeed (iron) is also Sura no. 57 of total 114 Suras of Quran, i.e in the middle. In addition no. 57 happens to be the atomic mass of one of the isotopes of iron.
The above point gives a hint that the collection and current order of suras in Quran is by divine design as Allah has the responsibility for keeping its integrity. The story in Islamic history, of collection of Quran by companions of Prophet and deciding upon the order of Suras is therefore doubtful. The below Ayat states that the collection of Quran is Allah’s responsibility:
75: 17 إِنَّ عَلَيْنَا جَمْعَهُ وَقُرْآنَهُ
“Surely, upon Us is its collection and its recital.”