Term | Definition |
Matter | a substance that has a mass and takes up space |
Mass | measured in kg |
Weight | the force that pulls mass to Earth;
measured in N (newton) |
Volume | the space that matter takes up;
measured in m^3 (meters cubed) or in chemistry still commonly L (liter) 1L = 0.001m^3 |
3 physical states (phases) of matter | solid, liquid, gas |
Physical properties | used to identify the phases of matter; color, density, melting point, boiling point, and solubility (in H20) |
Conservation of Matter | |
Solid | Highest organized molecules/atoms; fixed in crystal structure; least compressible state of matter; molecules/atoms have the least amount of potential energy |
Heating curve | Shows the change of temperature over time or input of energy |
Density | Describes how compact the atoms are within elements |
Homogenous matter | Consistent properties throughout; can be all the same element; can be a compound |
Compound | Two or more elements combined in fixed proportion; has its own set of properties; can only be separated by chemical means |
Homogenous mixtures | Components cannot easily (visually) be separated; components do NOT form chemical bonds |
Heterogenous mixtures | Components can be easily separated |
Mixtures | Properties are dependent on the ratio of the components and a mix of the component's properties; alloy is a mixture of metal (Ex. Brass or Steel) |
Separating mixtures by physical means include: | Sorting under a microscope, heat through distillation, magnet, centrifuge, chromatography, evaporation |
Separating mixtures by chemical means includes: | Adding a substance that forms a compound with only part of the unit |
Energy | Capability/ability to do work; 2 main types include potential and kinetic energy |
Potential energy | Based on position in relation to zero-position |
Kinetic energy | Energy of motion |
Chemical energy | Energy stored in chemical bonds |
Law of conservation of energy | Energy cannot be created or destroyed; it is just transformed into another type of energy |
| Now often called the conservation of mass, is a law of nature that states that matter/mass can neither be created or destroyed; only altered |
Jules | n SI unit |
Calories/kilocalories (cal/kcal) | The energy required to heat 1g of water 1 degree Celsius |
Temperature | A measurement of the average kinetic energy of all molecules in a system |
Fahrenheit | German chemist, Daniel Fahrenheit; 32 degrees is based on an ice + salt mix; 98.6 degrees is the body temperature; 212 degrees is the boiling point of water |
Celsius | Based on freezing of water = 0 degrees Celsius; boiling point of water = 100 degrees Celsius |
Kelvin | Directly related to the kinetic energy in a system; 0K (absolute 0) = no molecular movement exists |
Liquid | |
| Definite volume; ability to flow; fills its container (no definite shape); virtually incompressible; vapor equilibrium (constant evaporation and condensation) |
Calorimeter | Device used to record heating curves; insulated, closed container equipped with thermometer and stirrer |
Endothermic | Takes energy from outside |
Exothermic | Releases energy |
Torr | The unit used for vapor pressure |
Standard pressure | 760 torr |
Solid â> liquid | Melting/liquefaction/fusion |
Liquid â> solid | Crystallization/solidification |
Properties of gas | No definite shape or volume, is a fluid (ability to flow), easily compressible, less dense than a solid and liquid of the same volume, very small intermolecular attraction, molecules are in constant random motion, collisions between molecules are elastic |
Concentration | Amount of molecules per unit volume |
Phase diagram | Shows in which physical state of matter a substance will be at a certain Temperature-pressure combination |
Triple point | The temperature-pressure point at which a substance exists in all 3 phases |
Critical point | Temperature-pressure point above which the liquid and gas phase are indistinguishable (This phase is called: supercritical fluid) |