Nicotine dependence is now recognized as a psychoactive substance dependence disorder (DSM-IV, ICD-10). Under the DSM-IV criteria smokers are classified as dependent if they exhibit impaired control and continue to smoke despite awareness that it exacerbates a medical condition, and if they experience withdrawal symptoms when abstaining from smoking, or if they have a history of unsuccessful attempts at quitting.
The Earth's outer core is most likely made up of an iron-nickel alloy while the inner core mostly iron and a bit of nickel and cobalt. This is due to inferences that iron, cob â¦ alt and nickel are denser than other materials found at different levels in the structure of Earth, such as magnesium in the mantle.
Earth can be divided into three main layers: the core, the mantle and the crust. Each of these layers can be further divided into two parts: the inner and outer core, the upper and lower mantle and the continental and oceanic crust. Both the inner and outer core are made up of mostly iron and a little bit of nickel. The inner core is solid while the outer core is liquid. This liquid flowing deep down below us is what produces Earth's electromagnetic current. And it's pretty hot in the core-about as hot as the surface of the sun! The mantle is the thicket layer of Earth, making up about 85% of Earth's volume.