Chemistry Midterm
Chemistry Midterm
Matter: has mass and volume
– Pure Substance: elements and compounds (naturally), has a definite composition
– Mixtures: a combination of 2 or more elements or compounds, when combined do not lose their identities, can be separated by physical means
Heterogenous: mixture that does not have uniform properties (Ex. water and oil)
Homogenous: has uniform properties throughout (Ex. gasoline)
– Element: simplest, most pure type of matter that can not be broken down (if broken down it loses it properties) named after properties, people, places, and latin and greek names
– Atom: basic unit in chemistry, smallest unit in an element
– Molecule: smallest unit in a compound
– Compound: 2 or more elements chemically combined that takes on new properties, only can be separated by chemical means
– Metals: solid at room temp, luster, dense, high melting point, malleable, ductile, tenacious, combined metals called an alloy
– Non-Metal: poor conductors, brittle, many are gases, good insulators,
– Metalloids: semi-metals, good conductors of electricity, poor of heat
Describing Matter
– Quantitative: described with numbers (Ex. temp)
– Qualitative: the nature of something (Ex. color)
– Solid: molecules are tightly packed together, the distance between particles is small, attractive force is small, intermolecular density force is small.
– Liquid: molecules are further apart than solid, attractive forces are weaker, intermolecular forces are greater,
– Gas: molecules are x10 further apart than solid or liquid, greater molecular distance, molecules act independently
– Potential Energy: stored energy
– Kinetic Energy: energy in motion
– Physical Properties: characteristics of a substance that can be determined without changing its composition such as; color, size, mass, shape, state, density, boiling/melting
– Chemical Properties: describes an objects ability to react and form new substances such as; PH, reactivity
– Physical Change: change in physical properties such as size, shape, or change of states without changing its composition
-Chemical Change: occurs when a new substance