Terms

Unit 1A Terms

purity: clean, free from impurities

filtration: solid particles are separated from a liquid by passing the mixture through a material that retains the solid particles and allows the liquid to pass through. 

filtrate: the liquid collected after it has been filtered through the sand and gravel 

adsorb: to attract and hold onto a surface.

percent recovery: percent of original foul water sample recovered as purified water.

purified water: water that has been cleaned through oil-water separation, sand filtration, charcoal adsorption and filtration, and distillation. 

histogram: shows percent recovery obtained (by all laboratory groups in the class).

range: the difference between the largest and smallest values in a data set.

average/mean: average value found by adding all values together and dividing the sum by the total number of values. 

median: middle value by crossing the numbers off from each side. 

distillation: the process of separating salt from water through evaporation and condensation in a distillation apparatus. 

electrical conductivity: focuses on the presence of dissolved, electrically charged particles in water.

Tyndall Effect: the clarity of a water sample tested by passing a beam of light through each sample. Presence or absence of the Tyndall Effect. 

pure: clean, purified.

water cycle/hydrologic cycle: the cycle of water falling, evaporating into the air, condensing, and falling again.

direct water use: water that can be directly measured.

indirect water use: hidden uses of water.

gaseous state: water vapor in the air.

liquid state: in lakes, rivers, oceans, clouds, and rain.

solid state: ice.

surface water: a river or other body of water.

groundwater: a well- must be pumped to the surface.

aquifer: a water-bearing layer of rock, sand, or gravel.


Unit 1 B.1-B.4 Terms 


matter: anything that occupies space and has mass.
ex. solids, liquids, gases. 

physical properties: properties that can be observed and measured without changing the chemical makeup of the substance.
ex. density, freezing point of water, boiling point, melting point. 

density: the mass of material within a given volume. Water: 1g/mL, 1g/cm^3.

freezing/melting point (of water): 0°C or 32°F.

boiling point (of water): 100°C or 212°F.

aqueous solution: water-based solution.

surface tension: shows the strong intermolecular force that holds water molecules together.

mixture: when two or more substances combine and the substances retain their individual properties. The components of a mixture can be separated by physical means, such as filtration and adsorption.
ex. foul water 

heterogeneous mixture: composition is not the same, or uniform, throughout. (not evenly distributed). 
ex. foul water (coffee grounds sunk to bottom), suspension 

suspension: solid particles are large enough to settle out or can be separated by using filtration.
ex. water + coffee grounds and water + small pepper particles 

Tyndall Effect: the scattering of light that indicates that small, solid particles, are still in the water. 

collid: the small, solid particles that remain still in the water. Make liquid cloudy.
ex. whloe or low-fat milk 

homogeneous mixture: a mixture that is uniform throughout. (evenly distributed). 

solutions: homogeneous mixtures. (such as salt solution)

solute: salt in a salt solution; dissolved substance. 

solvent: water in a salt solution; dissolving agent. 

particulate level: the level of atoms and molecules.

atoms: building blocks of matter. all matter is made of atoms. 

element: matter that is made up of only one kind of atom.
ex. hydrogen, oxygen 

compound: a substance that is composed of the atoms of two or more elements linked together chemically in certain fixed proportions. 
ex. water (H20) 

chemical formulas: represent compounds. 
ex. C8H18

substance: all elements and compounds. has a uniform and definite composition, as well as distinct properties. 

molecule: the smallest unit of a molecular compound that retains the properties of that substance (smallest representation of the substance) ex: H2O molecule represents water. 

chemical bonds: hold atoms of molecules together. 

molecular compound: such as H2O

Unit 2 B.1 Terms

Atmosphere: provides nitrogen, oxygen, argon, neon

Hydrosphere: layer of water (oceans, clouds, ice caps, glaciers, lakes, rivers, underground water supplies) and some dissolved minerals

Lithosphere: solid part of Earth, provides the greatest variety of chemical resources like petroleum and metal-bearing ores

• Contains the crust (band of soil and rock that obtain the raw materials needed to build homes and more), mantle, and core

Ore: naturally occurring rock or mineral that can be mined and from which it is possible to extract metal or other minerals

Minerals: naturally occurring solid compounds containing the element or group of elements of interest

Unit 2 A.6-A.11 Terms

Atomic number: the number of proton in an atom; distinguishes atoms of different element

Nucleus: positively charged central region of an atom that contains protons and neutrons

Mass number: the sum of the number of protons and neutrons in the nucleolus of an atom of a particular isotope

Isotopes: atoms with the same number of protons but different number of neutrons

Periods: horizontal row in the periodic table; elements are listed in order of increasing atomic numbers and grouped according to similar properties

Periodic relationship: regular patterns among chemical and physical properties of elements arrayed in the periodic table

Group/ Family: vertical row in the periodic table (column); contains elements with similar properties

Alkali metal family: first column on the left side; highly reactive metal that forms an ECl chloride and E2O oxide

Noble gas family: right most group of the periodic table; consists of very unreactive (chemically inert) elements. Does not combine with any other group

Halogen family: form 1- ions; group containing fluorine, chlorine, and bromine in a column to the left of the noble gases

Unit 2 A.5 Terms

Combustion: chemical reaction with oxygen gas that produces thermal energy and light; burning

Conductor: a material that allows electricity (thermal energy) to flow through it

o   Conducts electricity à light bulb is on

Nonconductor: a material that does not allow electrical current (or thermal energy) to flow through it

o   Doesn’t conduct electricityà light bulb off

Malleable: flattens without shattering when struck

Brittle: shatters into pieces

Unit 2 A.1-A.4 Terms

Physical properties: a property that can be observed or measured without changing the identity of the sample of matter

o   Color, density, odder

Physical change: a material stays the same, but its form appears to have changed

o   Melting, boiling, bending

Chemical properties: properties only observed or measured by changing the chemical identity of a sample of matter

Chemical change: when a substance changes to one or more new substances

o   Burning wood, formation of a gas/solid

Luster: shinny and reflect light

Ductile: can be drawn into wires

Metals: a material possessing such as luster, ductility, conductivity, and malleability

o   Iron (Fe), tin (Sn), copper (Cu), zinc (Zn)

Nonmetals: a material possessing properties such as brightness, lack of luster, and nonconductivity; nonmetals are often insulators

o   Carbon (C) and oxygen (O)

Metalloids: a material with properties intermediate between those of metal and nonmetals

o   Silicon (Si) and germanium (Ge)