Unit 4 A.5, A.7, and A.9

Electronegativity is the tendency of an atom to attract shared electrons within a chemical bond. A cohesive force is the attractive force between molecules in a substance. A mixture is the combination of materials that retain its separate identity. A heterogeneous mixture is a mixture that is not uniform throughout. A suspension is a mixture containing large dispersed solid particles that can be separated by filtration. The tyndall effect is the scattering of light caused by reflection from suspended particles. Colloid is a mixture containing small solid particles that does not settle out. Milk would be an example of a colloid. Homogeneous means uniform throughout. A solution is a homogeneous mixture of two or more substances. When mixing salt with water, the salt is the solute, the dissolved substance, and the water is the solvent, the dissolving agent. In the water cycle a repetitive process of rainfall, run-off, evaporation, and condensation occurs in the Earth's crust and atmosphere. Direct water use is water consumed by an end user and indirect water use is the water consumed in the preparation, production, or delivery of goods. The water found on the Earth's surface is called surface water and water from underground is called groundwater. An aquifer is a water-bearing layer of rock, sand, or gravel.