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Water and Its Patterns on Earth's Surface

The Properties of Water branch demonstrates how water properties are affected by salt:

"Hands on" activities related to this concept map:

Potato Float Understand how the same object can both sink and float, depending on its density relative to a fluid

Liquid Rainbow Use analytical thinking by devising schemes to stack solutions of different densities

Can Sea Water Freeze? Freeze liquids of varying salinity & learn how it relates to the buoyancy of sea ice and icebergs

Properties of Fresh & Sea Water Conduct experiments on the boiling point, freezing point, and heat capacity of fresh water and sea water

Density: Sea Water Mixing & Sinking Use temperature-salinity (T-S) diagrams to understand the importance of seawater density studies

Electrolysis of Salt Water Conduct an experiment to see that water can be split into its constituent ions through the process of electrolysis

The Nature of Salt Students research the structure of salt to understand the difference between molecular compounds and ionic compounds

Questions or comments? Contact Annette deCharon, Senior Science Educator and Aquarius EPO Manager

Glossary Words

brine: Water saturated with or containing large amounts of a salt, especially sodium chloride.

buoyancy: In physics, an upward force on an object immersed in a fluid (i.e. a liquid or gas), enabling it to float or at least to appear to become lighter. If the buoyancy exceeds the weight, then the object floats; if the weight exceeds the buoyancy, the object sinks.

density: Mass per unit volume of a substance. Usually expressed as grams per cubic centimeter (gm/cm^3).

freezing point: Temperature at which a liquid of specified composition solidifies under a specified pressure.

heat capacity: The amount of heat required to raise the temperature of one gram of a substance by one degree Celsius without change of phase.

heat of vaporization: The thermal energy absorbed by a liquid at its boiling point as it changes to a gas.

latent heat of fusion: The amount of thermal energy associated with vaporizing a liquid or a solid, or condensing a vapor.

practical salinity unit (PSU): Used to describe the concentration of dissolved salts in water, the UNESCO Practical Salinity Scale of 1978 (PSS78) defines salinity in terms of a conductivity ratio, so it is dimensionless. Salinity was formerly expressed in terms of parts per thousand (ppt) or by weight (parts per thousand or 0/00). That is, a salinity of 35 ppt meant 35 pounds of salt per 1,000 pounds of seawater. Open ocean salinities are generally in the range between 32 and 37.

salinity: A measure of the quantity of dissolved solids in ocean water. In general, salinity reflects the total amount of dissolved solids in ocean water in parts per thousand by weight after all carbonate has been converted to oxide, the bromide and iodide to chloride, and all the organic matter oxidized.

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