Average mass, in pounds, of an African elephant

Number of 'essential' amino acids

Number of miles between Mars and its moon Phobos at its closest

Number of carbon atoms in buckminsterfullerene (buckyball)

Atomic number of element mendelevium (Md)

Number of fluid ounces (U.S.) in a fluid quart (U.S.)

Avogadro constant defining entities per mole of a substance

The speed of light, in meters per second

The speed of sound at sea level, in meters per second

The boiling point of water, in °F, at atmospheric sea level pressure

The smallest primitive abundant number

Acceleration of an object falling freely under Earth's gravitational pull, in m/s^2

Number of seconds in a week

Molecular weight, in grams per mole, of a water molecule

Absolute zero, in the Kelvin temperature scale

'Classic' number of organism kingdoms, as established by the ISPC

Number of chromosomes in a normal human sperm cell

Mass, in pounds, of the Mars Curiosity rover

World population (as of September 1, 2012)

Number of millimeters in a mile