Term | Definition |
matter | anything that has mass and takes up space |
non-matter | sound, light, and heat |
property | characteristic of a substance that can be observed |
weight | force of gravity acting on an object |
density | amount of mass per unit volume |
intensive property | do not depend on amount of substance being tested/observed |
1.0 g/mL | water's density |
refraction | bending of a light wave as it passes from one medium to another |
chemical properties | a property that can only be observed by changing the identity of the substance |
flammability, ability to rust, reactivity with vinegar | examples of chemical properties |
optical properties | color and refractive index |
non-optical properties | surface wear, striations from manufacturing, thickness, surface film or dirt, hardness, density |
resistant to all but fluorine and very strong bases | chemical properties of glass |
glass | fusion of sand, soda, and lime that produces a transparent solid when cooled |
physical property | can be observed without changing a substance's identity |
element | substance that only has one type of matter in it |
element is a building block of matter | how are matter and element related? |
atom | smallest particle of an element that can exist and still retain its identity |
compound | two or more elements joined chemically |
solid, liquid, gas | three states of matter |
amount of space between particles (freezing, melting, and boiling points) | what chemical property of a substance determines its state? |
physical because the chemical compositions stay the same | are changes of state physical or chemical changes? |
wavelength | length from crest to crest or trough to trough |
different colors come from different wavelengths of light | how is color related to the behavior of light? |
wavelength or frequency | what property distinguished different types of electromagnetic radiation from one another? |
temperature | measure of heat intensity |
weigh it | how is the mass of an object determined? |
hardness, color, density | examples of intensive property |
borosilicate glass | 5% borax is added to resist breaking when heated or cooled |
colored glass | metal oxides or colloidal iron and sulfur are added to change its color |
lead glass | lead increases refractive index and density |
flat glass | made by a "float glass process"; molten glass is floated on a pool of tin while cooling (commonly found in doors and windows) |
laminated glass | two sheets of glass with plastic between them (used in windshields) |
tempered safety glass | designed to break into tiny pieces (used in car side window) |
away | glass acts initially as an elastic surface and bends in which direction when force is applied |
radial cracks | form first and are propagated in short segments on the side opposite the force |
concentric cracks | come from continued pressure on the same side as the force applied |
refractive index | ratio of velocity of light in a vacuum to velocity of light in a given substance |
sand | main ingredient in ordinary glass |
soda lime glass | what kind of glass is used most commonly in bottles and windows? |
match it with a bigger piece of the glass like a jigsaw puzzle | what is the only way to individualize glass fragments found at a crime scene to a single source? |
density and refractive index | what physical properties are used most often to characterize glass particles? |
flotation | method for measuring density |
immersion method | how can a forensic scientist determine the refractive indices of suspect glass fragments? |
Liter | basic unit |
radial cracks then concentric cracks | when an object strikes a piece of glass, how does it fracture? |
becke lines | edges of lines |
soil | any disintegrated surface material, natural and/or artificial, that lies on or near the earth's surface |
color and texture | visual comparison of identification technique |
mineral | naturally occurring crystalline solid |
rock | combination of minerals |
igneous, metamorphic, sedimentary | types of rock |
density-gradient tube | way to analyze soil |
density-gradient tube | a glass tube filled from bottom to top with liquids of successively lighter densities |