Periodic Table of the Elements

Geological Time Clock

Geological Time Chart

Measurements and the Metric System

Table 1. Measurements and the Metric System

Measurement	Unit	Abbre-viation	Metric Equivalent	Approximate Standard Equivalent
Length	nanometer	nm	1 nm = 10−9 m	1 mm = 0.039 inch 1 cm = 0.394 inch 1 m = 39.37 inches 1 m = 3.28 feet 1 m = 1.093 yards 1 km = 0.621 miles
	micrometer	µm	1 µm = 10−6 m
	millimeter	mm	1 mm = 0.001 m
	centimeter	cm	1 cm = 0.01 m
	meter	m	1 m = 100 cm 1 m = 1000 mm
	kilometer	km	1 km = 1000 m
Mass	microgram	µg	1 µg = 10−6 g	1 g = 0.035 ounce 1 kg = 2.205 pounds
	milligram	mg	1 mg = 10−3 g
	gram	g	1 g = 1000 mg
	kilogram	kg	1 kg = 1000 g
Volume	microliter	µl	1 µl = 10−6 l	1 ml = 0.034 fluid ounce 1 l = 1.057 quarts 1 kl = 264.172 gallons
	milliliter	ml	1 ml = 10−3 l
	liter	l	1 l = 1000 ml
	kiloliter	kl	1 kl = 1000 l
Area	square centimeter	cm2	1 cm2 = 100 mm2	1 cm2 = 0.155 square inch 1 m2 = 10.764 square feet 1 m2 = 1.196 square yards 1 ha = 2.471 acres
	square meter	m2	1 m2 = 10,000 cm2
	hectare	ha	1 ha = 10,000 m2
Temperature	Celsius	°C	—	1°C = 5/9 × (°F - 32)