click below
click below
Normal Size Small Size show me how
Chapter 1: Matter
| Term | Definition |
|---|---|
| Natural Laws | Concise statements that summarize observations of certain natural phenomena. |
| Hypothesis | A tentative (uncertain) explanation of a series of observations or of a natural law. |
| Theory | A model used to explain and make further predictions about natural phenomena. |
| Scientific Method | The general sequence of activities that lead to the advancement of scientific knowledge. |
| Matter | Anything that occupies space and displays the properties of mass. |
| Composition | Refers to the components and their relative proportions in a sample of matter. |
| Properties | Qualities or attributes that can be used to distinguish one sample of matter from others. |
| Physical Change | One or more physical properties of a sample of matter change, but the composition remains unchanged. |
| Chemical Change/Reaction | A process in which one set of substances (reactants) is transformed into a new set of substances (products). |
| Chemical Property | The ability (or inability) of a sample of matter to undergo a particular chemical reaction. |
| Atoms: | The basic building block of matter. |
| Element | A substance composed of a single type of atom. It cannot be broken down into simpler substances. |
| Compounds | A substance made up of two or more elements. |
| Molecule | A group of bonded atoms held together by covalent bonds and existing as a separate entity. |
| Substances | Have a constant composition and properties. Can either be elements or compounds. |
| Homogeneous Mixture | A mixture of elements and/or compounds that has a uniform composition and properties within a given sample. |
| Heterogeneous Mixture | A solution in which the components separate into physically distinct regions of differing properties and often differing composition. |
| Solid | A state of matter, in which atoms or molecules are in close contact, often in highly organized arrangement. |
| Liquid | A state of matter, in which atoms or molecules are in close proximity. A liquid occupies a definite volume, but has the ability to flow and assume the shape of its container. |
| Gas | A state of matter, in which atoms or molecules are generally much more widely separated than in liquids and solids. No definite shape or volume. |
| Mass | Describes the quantity of matter in an object. |
| Celcius | A temperature scale. 0°C is the melting point of ice. 100°C is the boiling point of water. |
| Fahrenheit | A temperature scale. 32°F is the melting point of ice. 212°F is the boiling point of water. |
| Kelvin | An absolute temperature, there are no negative Kelvin temperatures. No ° is used. The lowest attainable temperature is 0K = -273.15°C = -459.67°F (the temperature at which molecular motion stops). |
| Density | A physical property obtained by dividing the mass of a material or object by its volume. |
| Extensive Property | A property whose value depends on the quantity of matter observed, like mass or volume. Dependant Properties |
| Intensive Property | A property that is independent of the quantity of matter being observed, like temperature and density. Independent Properties |
| Systematic Errors | An error that recurs regularly in a series of measurements because of an inherent error in the measuring system. Eg. Faulty Calibration |
| Random Errors | An error made by the experimenter in performing an experimental technique or measurement. |
| Precision | The degree of reproducibility of a measured quantity. The closeness of agreement among repeated measurements. |
| Accuracy | The "closeness" of a measured value to the true or accepted value of a quantity. |
| Significant Figures | Digits in an experimentally measured quantity that establish the precision with which the quantity is known. |