Some facts that you might want to include in the next update of the OP, Hydro. Also, an idea for a change of the title: "(Almost) Everything you wanted to know about Nuclear Weapons, but were afraid to ask".
Fusion bombs use a fission detonation to compress the hydrogen isotopes down to a point where they begin to fuse.
Hafnium bombs are theoretical at this point, but if the energy from the isomers could be harnessed, in theory, it could be used to produce a pure fusion weapon.
Neutron bombs are different from Hafnium bombs, in that they have been achieved, and are usually fission-fusion in design, but with the X-ray mirrors made of a neutron-transparent material, so as to allow said neutrons to escape. This allows neutron bombs to emit around 10 times the amount of neutrons than a standard nuclear weapon of the same yield. Neutron bombs are intended to focus more on killing people than destroying targets, and are generally of a lower explosive yield than other nukes, though the damage is not negligible, since the yields are usually in the kiloton range. They were initially developed as a way to kill tank crews in massed columns, as the metal armor would protect against most other forms of radiation, while neutron radiation is insidious in that it will render the metal armor radioactive, thus guaranteeing lethal exposure.
Nuking a city won't kill everybody inside it. A nuke detonated in the lower atmosphere will usually have the following energy distribution:
-Blast—40–50% of total energy
-Thermal radiation—30–50% of total energy
-Ionizing radiation—5% of total energy (though up to 50% in a neutron bomb)
-Residual radiation—5–10% of total energy
Generally, the denser the medium in which you're detonating, the more powerful the blast wave will be, though at the cost of limiting its radius.
Mushroom clouds are generally only seen in lower atmospheric detonations, where the fireball interacts with the ground.
Most non-reinforced or blast-resistant buildings will suffer damage and/or be destroyed when subjected to 5-10 psi of pressure (though buildings directly beneath the point of detonation in an airbust have a good chance of remaining standing, as will most buildings designed to survive an earthquake). Your average person CAN survive this, so there will almost certainly be survivors of any city that gets nuked. Though they will probably not survive unscathed. Typical injuries to expect from survivors of the blast would be: burst eardrums, blindness, various forms of trauma from objects hitting the body, other injuries associated with pressure, and obviously, burns (due to the extreme amounts of visible, IR, and UV light produced by the explosion).
Though many will survive, many will not. For rough estimates, assume that 50% of the total casualties in the affected area at the time will die within the first 24 hours, with the rest dying in the next few months afterwards. These numbers were seen in Hiroshima and Nagasaki. According to the Hiroshima health department, of those who died on the day of detonation, 60% died from flash/flame burns, 30% from flying and falling debris, and 10% from other causes. For next few months afterwards, the biggest killers were the effects of the burns, radiation sickness, and other injuries compounded by illnesses. US estimates put the distribution at 20-30%, 15-20%, and 50-60%, for the respective causes.
The symptoms of Acute Radiation Syndrome (aka: Radiation sickness), fall into three broad categories, and include: Hematopoietic: aplastic anemia (drop in the number of blood cells), which can lead to infections, bleeding, and anemia. These symptoms can complicate injuries directly resulting from a blast, and can be apparent with doses as low as 0.25 Gy, though they might not be felt below 1 Gy; Gastrointestinal: nausea, vomiting, loss of appetite, and abdominal pain, the onset of which within around two hours of exposure usually indicates a lethal dose, and usually occurs with doses of 6-30 Gy; Neurovascular: dizziness, headache, and decreased level of consciousness. Usually occurs with doses greater than 30 Gy, but can occur with doses as low as 10 Gy, and has an onset very quickly (within minutes to a few hours), and with an absence of vomiting. Is almost always fatal.
One of the most dangerous fallout isotopes is Iodine-131 (a major fission product of both Uranium and Plutonium), which can be absorbed into the thyroid gland and will cause much damage once there. Its recommended to avoid exposure for approximately ten of its half lives, or about 80 days. Potassium iodide is also an effective way to keep the body from absorbing I-131.
Nuclear winter is probably not as likely as once thought, due to the lack of density of combustible materials in modern cities, combined with their relative rarity (only one nuclear-induced firestorm has ever been recorded, and that was the bombing of Hiroshima). In order for a firestorm to form, an area needs to have 40kg of combustibles per square meter. The explanation for how nuclear winter would occur depends on extremely high temperature soot from firestorms being lofted into the upper atmosphere, and blocking out the sun, in similar manner to an impact winter or volcanic winter. Similar predictions were made regarding Iraqi oil wells prior to and during the First Gulf War, but did not pan out, because the smoke could not reach the stratosphere.
Further reading and more in-depth coverage of the topics covered can be found in the following sources:
https://en.wikipedia.org/wiki/Nuclear_warfare
https://en.wikipedia.org/wiki/Neutron_bomb
https://en.wikipedia.org/wiki/Acute_radiation_syndrome
https://en.wikipedia.org/wiki/I-131#Tre ... prevention
https://en.wikipedia.org/wiki/Effects_o ... man_health
https://en.wikipedia.org/wiki/Firestorm
https://en.wikipedia.org/wiki/Nuclear_winter
https://en.wikipedia.org/wiki/Effects_o ... explosions
