Term | Definition |
chemistry | the science of matter |
matter | any object that has mass and occupies space |
theory | a well established hypothesis |
scientific law | a statement of natural phenomenon where no exceptions are known under any given circumstances |
amorphous solids | solid without shape or form |
gas | indefinite volume and no fixed shape |
attractive forces | hold the particles together and give matter its appearance of continuity; strongest in solids, giving them rigidity, weaker in liquid, and weakest in gases. |
pure substance | a definite, fixed composition and is either an element or a compound |
homogeneous mixture | |
heterogeneous matter | consists of two or more physically distinct phases |
phase | a homogeneous part of a system separated from other parts by a physical boundary |
mixture | a combination of two or more pure substances and can be homo or heterogeneous |
scientific notation | a way to write very large or small numbers (measurements) in a compact form |
measurement | a quantitative observation |
metric or international system | standard system of measurements for mass lengths, time and other physical quantities |
meter | standard unit of length of metric system |
element | fundamental substance that cannot be broken down by chemical means into simpler substance; building blocks of matter |
atom | smallest unit of an element that retains its properties and chemical behavior; made of subatomic particles |
Dimitri Mendeleev | developed the periodic table in 1869 |
metals | solids at room temperature (except mercury); shiny, good conductors of heat and electricity; malleable (can be shaped); ductile; have a high melting point and density |
nonmetals | not shiny; have fairly low melting points and densities; poor conductors of heat and electricity; can combine with each other to form molecullar compounds |
metalloids | have properties between metals and nonmetals |
compound | a substance containing two or more elements that are chemically combined in a definite proportion; decompose chemically into simpler |