A nuclear weapon is an explosive device that derives its destructive force from nuclear reactions, either fission or a combination of fission and fusion. The first thermonuclear ("hydrogen") bomb test released the same amount of energy as approximately 10,000,000 tons of TNT.

Two nuclear weapons have been used in the course of warfare, both times by the United States near the end of World War II. On 6 August 1945, a uranium gun- type fission bomb code-named "Little Boy" was detonated over the Japanese city of Hiroshima.

Three days later, on 9 August, a plutonium implosion- type fission bomb code-named "Fat Man" was exploded over Nagasaki, Japan. These two bombings resulted in the deaths of approximately 200,000 people—mostly civilians—from acute injuries sustained from the explosions.

Hair The losing of hair quickly and in clumps occurs with radiation exposure at 200 rems or higher. Brain Since brain cells do not reproduce, they won't be damaged directly unless the exposure is 5,000 rems or greater. Like the heart, radiation kills nerve cells and small blood vessels, and can cause seizures and immediate death. Thyroid The certain body parts are more specifically affected by exposure to different types of radiation sources. The thyroid gland issusceptible to radioactive iodine. In sufficient amounts, radioactive iodine can destroy all or part of the thyroid. By taking potassium iodide can reduce the effects of exposure.

A supercritical mass of fissile material, and a chain reaction will rapidly produce neutrons that, in turn, generate more fission and neutrons. The challenge is to bring two subcritical masses together quickly before the energy released by the initial fission blows the masses apart and stops the chain reaction.

WORKING OF FAT MAN BOMB Compared to the one used on Hiroshima, the Nagasaki bomb was rounder and fatter. It was called "Fat Man." The material used was plutonium 239. The fission of slightly more than one kilogram of plutonium 239 is thought to have released destructive energy equivalent to about 21,000 tons of TNT.

WORKING OF LITTLE BOY Due to its long, thin shape, the Hiroshima bomb was called “Little Boy”. The material used was uranium 235. It is believed that the fission of slightly less than one kilogram of uranium 235 released energy equivalent to approximately 15,000 tons of TNT.

EXPLOSION AT HIROSHIMA/NAGASAKI

WHAT IS A CHEMICAL WEAPON? A chemical weapon is a device that uses chemicals formulated to inflict death or harm on human beings. They are classified as weapons of mass destruction though they are separate from biological weapons(diseases), nuclear weapons, and radiological weapons (which use radioactive decay of elements).

The Imperial Japanese Army frequently used chemical weapons. According to historians Yoshiaki Yoshimi and Kentaro Awaya, gas weapons, such as tear gas, were used only sporadically in 1937 but in early 1938, the Imperial Japanese Army began full-scale use of sneeze and nausea gas (red), and from mid-1939, used mustard gas (yellow) against both Kuomintang and Communist Chinese troops

EFFECTS ON HUMANITY Since the start of World War I, chemical weapons and agents have killed or injured an estimated 1.5 million people. Those attacks have included chlorine, mustard gas, and phosgene in WWI; napalm and Agent Orange in World War II and the Vietnam War; sulfur mustard gas in WWI, WWII, and the Iran- Iraq War; and sarin gas by Iraq against its Kurdish population in the 1980s. Chemical weapons have been regulated and banned during warfare by the Geneva Protocol in 1925 and the Chemical Weapons Convention of 1992.

CHEMISTRY BEHIND CHEMICAL WEAPONS Chemical weapon is any weapon that uses a manufactured chemical to kill people. The first chemical weapon used effectively in battle was chlorine gas, which burns and destroys lung tissue. Chlorine is not an exotic chemical. Most municipal water systems use it today to kill bacteria. It is easy to manufacture from common table salt. In World War II, the German army released tons of the gas to create a cloud that the wind carried toward the enemy.