Chemical properties. Calcium is a moderately active element. It reacts readily with oxygen to form calcium oxide (CaO): Calcium reacts with the halogensâ fluorine, chlorine, bromine, iodine, and astatine, The halogens are the elements that make up Group 17 (VIIA) of the periodic table.
The bombing of Hiroshima and Nagasaki. On August 6, 1945 the US dropped an atomic bomb (Little Boy) on Hiroshima in Japan. Three days later a second atomic bomb (Fat Man) was dropped on the city of Nagasaki.These were the only times nuclear weapons have been used in war.Reasons for the bombing.Many reasons are given as to why the US administration decided to drop the atomic bomb on Hiroshima and Nagasaki. Reasons include the following: 1  The United States wanted to force Japan's surrender as quickly as possible to minimize American casualties.hese were the only times nuclear weapons have been used in war. Reasons for the bombing. Many reasons are given as to why the US administration decided to drop the atomic bomb on Hiroshima and Nagasaki.
On August 6, 1945 an atomic bomb named Little Boy was dropped on Hiroshima, Japan. The explosion was huge, the city was destroyed, and tens of thousands of people were killed. The bomb was dropped by a plane named the Enola Gay which was piloted by Colonel Paul Tibbetts. The first bomb dropped on Hiroshima was made from uranium. 2  The bomb dropped on Nagasaki was made from plutonium, which was even more powerful than uranium. 3  It is thought that at least 135,000 people died from the Hiroshima explosion and another 70,000 in Nagasaki.