You searched for: “unit
unit
A standard measurement; for example, the standard unit of inches is used to measure length in the U.S. Conventional System and centimeters and meters are used in most of the other countries.
This entry is located in the following unit: Measurements and Mathematics Terms (page 10)
(when visiting old graveyards and examining the epitaphs on gravestones, there are certain words and phrases which could be difficult or impossible to understand without knowing what the words in this unit mean)
(the study of the deep seas or oceans involves the abyss or the "deep seas" which cover almost two-thirds of the earth's surface; showing applicable scientific terminology in this unit)
(Various living organisms are organized from the smallest unit of cells to form tissues which form organs and organs work together to form organ systems)
Word Entries containing the term: “unit
angstrom unit, symbol: A or Å
A length equal to 10-10 meters or one-ten-millionth of a millimeter, used for atomic measurements and the wavelengths of electromagnetic radiation.

A unit that measures the wavelength of light and equals 0.00000001 of a centimeter. Blue light has a wavelength of about 4400 angstroms, yellow light 5500 angstroms, and red light 6500 angstroms.

This entry is located in the following unit: Science and Technology (page 1)
astronomical unit, A.U. or a.u.
1. The average distance from the earth to the sun, which equals 149,597,870 kilometers or 92,955,800 miles.

For simplicity, an AU is usually rounded off to 93,000,000 miles or 149,637,000 kilometers.

2. An astronomical unit is used to describe planetary distances.

Light travels this distance in approximately 8.3 minutes.

British thermal unit, Btu
An imperial unit of heat, now replaced in the SI system by the joule (one British thermal unit is approximately 1,055 joules).

Burning one cubic foot of natural gas releases about 1,000 Btu of heat.

This entry is located in the following unit: Measurements and Mathematics Terms (page 3)
British Thermal Unit; BTU, Btu
The amount of heat required to raise the temperature of one pound of water one degree Fahrenheit; equal to 252 calories.
This entry is located in the following unit: Photovoltaic Conversion Efficiency Terms + (page 3)
cleanliness unit
A unit for measuring air pollution.

The number of particles greater ghan 0.5 micrometers in diameter per cubic foot of air.

Normally, the measure is the weight of contaminants per cubic meter of air.

This entry is located in the following unit: Measurements and Mathematics Terms (page 4)
International System of Units, SI; Système Internationale d’Unités
All systems of weights and measures, metric and non-metric, are linked through a network of international agreements supporting the International System of Units.

The International System is called the SI, using the first two initials of its French name Système International d'Unités.

The primary agreement is the "Treaty of the Meter" or the Convention du Mètre, signed in Paris on May 20, 1875.

Forty-eight nations have signed the treaty, including all the major industrialized countries. The United States is a charter member of the metric club, having signed the original document back in 1875.

Each SI unit is represented by a symbol, not an abbreviation. The use of unit symbols is regulated by precise rules.

These symbols are the same in every language of the world; however, the names of the units themselves vary in spelling according to national procedures; therefore, it is correct for Americans to write meter and Germans to write Meter, and it is also correct for the British to write metre, Italians to write metro, and Poles to write metr.

There is no official spelling of the SI units; however, the SI does provide the names, the definitions, and the symbols of the units which must be followed even when the spellings are different as shown below.

The fundamental SI unit of length has numerous spellings

  • meter (American English, Danish, Dutch, German, Hungarian, Norwegian, Slovak, and Swedish)
  • metr (Czech, Polish, Russian, Ukrainian)
  • metras (Lithuanian)
  • metre (British, Australian, Canadian and New Zealand English; French)
  • metri (Finnish)
  • metro (Basque, Italian, Portuguese, Spanish)

A list of elements associated with the International System of Units (SI)

  • ampere (unit of measurement)
  • are (unit of area measurement)
  • atomic second
  • candela (cd) (SI unit of measurement)
  • centimeter (cm) (unit of measurement)
  • coulomb (unit of energy measurement)
  • farad (unit of measurement)
  • gram (gm or g) (measurement)
  • hectare (unit of measurement)
  • henry (unit of energy measurement)
  • hertz (unit of measurement)
  • joule (unit of energy measurement)
  • kelvin (K) (unit of measurement)
  • kilogram (kg) (unit of measurement)
  • kilometer (km) (unit of measurement)
  • liter (l) (unit of measurement)
  • lumen (unit of energy measurement)
  • lux (unit of energy measurement)
  • megohm (electronics)
  • meter (m) (measurement)
  • metric ton (unit of weight)
  • micrometer (unit of measurement)
  • millimeter (mm) (unit of measurement)
  • mole (chemistry)
  • nanometer (unit of measurement)
  • nanotesla (physics)
  • newton (unit of measurement)
  • ohm (unit of energy measurement)
  • pascal (Pa ) (unit of energy measurement)
  • second (unit of time)
  • siemens (S) (unit of energy measurement)
  • tesla (unit of energy measurement)
  • unit (measurement)
  • volt (unit of measurement)
  • watt (unit of measurement)
  • weber (unit of measurement)

Compiled partly from information located at the
Encyclopedia Britannica on line.
This entry is located in the following unit: Measurements and Mathematics Terms (page 7)