Relative dating and radiometric dating are used to determine age of fossils and geologic features, but with different methods. Relative dating uses observation of location within rock layers, while radiometric dating uses data from the decay of radioactive substances within an object.Know More
Relative dating observes the placement of fossils and rock in layers known as strata. Basically, fossils and rock found in lower strata are older than those found in higher strata because lower objects must have been deposited first, while higher objects were deposited last. Relative dating helps determine what came first and what followed, but doesn't help determine actual age.
Radiometric dating, or numeric dating, determines an actual or approximate age of an object by studying the rate of decay of radioactive isotopes, such as uranium, potassium, rubidium and carbon-14 within that object. Radioactive isotopes decay at a fixed rate. This rate provides scientists with an accurate measurement system to determine age. For example, carbon dating is used to determine the age of organic materials. Once something dies, it ceases taking in new carbon-14, and the existing carbon-14 within the organism decays into nitrogen at a fixed rate. Scientists measure the proportion of carbon-14 left in the organism to determine its age.Learn more about Atoms & Molecules
The difference between ferric and ferrous iron is that ferric iron is in a plus-3 oxidation state, while ferrous iron is in a plus-2 oxidation state. This means that ferric iron needs to share three electrons with an oxygen molecule to make the ion neutral, while ferrous iron only needs two more electrons. With the addition of oxygen, the ferrous ion can easily become a ferric ion.Full Answer >
An element is a pure substance that consists entirely of one type of atom. An atom is the smallest amount of a particular element that can be identified as that element.Full Answer >
The difference between exothermic and endothermic reactions is found in their names: "endo" means to draw into itself, whereas "exo" means to emit. All chemical reactions either release or use energy, which can be in the form of heat or light. Endothermic reactions need energy that is supplied by their surroundings, whereas exothermic reactions give off energy. Exothermic reactions heat up their surroundings, while endothermic reactions cool them down.Full Answer >
Alkanes are hydrocarbons with single covalent bonds between the carbon atoms, while alkenes are hydrocarbons with one or more double covalent bonds between the carbon atoms. Hydrocarbons are either aliphatic or aromatic. Alkanes and alkenes are aliphatic hydrocarbons, which means they are both formed when oils or fats are degraded chemically.Full Answer >