The National Science Resources Center says that density is one of the characteristic properties of an object, which, when compared to the densities of other known objects, allows an investigator to identify the materials from which it is made. While several materials may have similar densities, this property allows an individual to rule out unlikely candidates and use further tests to confirm identification.
Reference.com defines density as the ratio of an object's volume to its mass. Several factors affect density and it sometimes varies slightly from one sample to the next. Density varies with temperature as many materials expand upon heating. In addition, the density of a gas increases as pressure increases. When speaking of the density of a gas, scientists often specify the standard temperature and pressure to eliminate these variables. Managing these conditions is essential if one is using density to identify a gas.
Specific gravity relates to density. It is the ratio of the material as compared to water and carries no units. About.com says objects with specific gravities greater than 1 sink in water, while those with a specific gravity of less than 1 float. This quick test of nonsoluble items helps to eliminate possible choices when identifying a solid.Learn More
Lithium has a boiling point of 1,342 degrees Celsius and a freezing point of 180.5 degrees Celsius. Due to lithium's high freezing point, it exists as a solid at room temperature.Full Answer >
The addition of heat raises the temperature of a material by a certain amount. The amount of heat needed to raise the temperature of a unit mass or volume of material by one degree is called the specific heat of the material.Full Answer >
A classic example of an endergonic reaction is a synthesis reaction, where simple molecules combine to form complex compounds. An endergonic reaction requires the input of free energy to initiate the process.Full Answer >
When particles are heated, they absorb energy, which in turn causes them to start moving around more. All atoms and molecules move constantly. Solids move the least, with particles mostly just vibrating, and gas particles move the most, typically freely bounding around in open space.Full Answer >