Dr. Darrin Lew

SI Units

Quantity

Unit

Symbol

Amount of substance

mole

mol

Electric current

ampere

a

Energy

joule

J

Length

meter

m

Mass

kilogram

kg

Power

watt (1 J/s)

w

Pressure

pascal

Pa

Radioactive decay

becqerel

Bq

Temperature

kelvin

K

Time

second

s

Prefixes

Name

Symbol

Multiplying factor

atto

a

10-18

femto

f

io-15

pico

P

io-12

nano

n

10-9

micro

M

io-Ä

milli

m

10-3

centi

c

10-2

deci

d

10-1

deka

da

1o

hecto

h

102

kilo

k

103

mega

M

10Ä

giga

G

109

tera

T

1012

peta

P

1015

exa

E

1018

Name and symbol

Value acre angstrom (A) atmosphere (atm) bar barrel (petroleum) = 42 gal = 306 lb calorie (cal)

curie (Ci)

electron-volt (eV)

gallon (gal)

hectare metric ton—see tonne mile (mi)

ton (U.S. long); 2240 pounds ton (U.S. short); 2000 pounds tonne (metric ton); 2205 pounds

0.4047 hectare 10-10mor 0.1 nm 1.01325 x 105 Pa 105 Pa 0.159 m3 4.184 J

3.70 x 1010 Bq 1.602 x 10-19J 0.3048 m 3.786 x 10-3 m3 104m2

1609.344 m 1.016 x 103 kg 9.072 x 102 kg 1 x 103 kg