# Chemistry SI Units and Conversions  This article discusses the SI base units of measure commonly used in chemistry, including the time unit of second (s), length unit of meter (m), mass unit of kilogram (kg), and

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## About Chemistry SI Units and Conversions

PowerPoint presentation about 'Chemistry SI Units and Conversions'. This presentation describes the topic on This article discusses the SI base units of measure commonly used in chemistry, including the time unit of second (s), length unit of meter (m), mass unit of kilogram (kg), and. The key topics included in this slideshow are . Download this presentation absolutely free.

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Slide1Chemistry: SI  Units  & Conversions Chemistry:  SI  Units  & Conversions

Slide2SI Base  Units  of  Measure commonly  used  in  chemistry SI  Base  Units  of  Measure commonly  used  in  chemistry • Time: second (s) • Length,distance: meter (m) • Mass: kilogram (kg) – In class, we consider the “base unit” to be grams. • Volume: liter (l) • Temperature: Kelvins (K)  note: no degree symbol – In chemistry lab, we use the Celsius temperature scale. (  °C)

Slide3Derived Units Derived  Units • A derived unit is one in which the units are combined mathematically. – Volume: cubic centimeter (cm 3 ) • (cm x cm x cm) – Area: square meter (m 2 ) • ( m x m) – Density: mass    volume

Slide4Converting Celsius  to  Kelvin Converting  Celsius  to  Kelvin Kelvins =   C + 273 °C = Kelvins - 273

Slide5Prefixes for  SI  Units Prefixes  for  SI  Units • P r e f i x e s  f o r  u n i t s  s m a l l e r  t h a n  1 : – m i c r o  (  )    1  X  1 0 - 6   o r – m i l l i  ( m )   1  X  1 0 - 3    o r – c e n t i  ( c )   1  X  1 0 - 2  o r – d e c i  ( d )   1  X  1 0 - 1  o r • P r e f i x e s  f o r  u n i t s  l a r g e r  t h a n  1 : – k i l o  ( k )   1  X  1 0 3  o r  1 , 0 0 0

Slide6Conversion Using  the  Factor-Labeling  Method  : (Dimensional  Analysis) Conversion  Using  the  Factor-Labeling  Method  : (Dimensional  Analysis) Problem: Convert 32.05 cm to m Step 1 : write down the starting measurement: number and unit! Step 2 : Convert from this prefix to the base unit. (This means meters, liters or grams.) X Step 3 : Cancel the units that divide each other out. Step 5  If you have arrived at the target unit, you are done! Be sure to include the unit and significant figures in your answer! = Step 4 : Perform the math… divide by the numbers on the bottom, multiply by the numbers on the top! Starting unit Target unit

Slide7Practice!Practice! Convert 0.00450 km to cm X ? X = T h e  c o r r e c t  a n s w e r  i s 4 5 0  c m ,  b u t  t h a t ’ s  o n l y 2  s i g  f i g s … .  ? ? ? ? ? U s e  s c i e n t i f i c  n o t a t i o n  t o c o r r e c t  t h e  s i g  f i g s ! 4.50 x 10 2  cm