What are some tools scientist use to look at the world around them? Do you have any in your home?

Le Systeme International d'Unites (1960) QuantityBase Unit NameSymbol LengthMeterm MassKilogramkg TimeSeconds TempKelvinK AmountMolemol Electric currentAmpereA

QuantityDerivationAbbreviation Aream x mm2m2 Volumem x m x mm3m3 Speeddistance/timem/s Densitymass/volumekg/m 3 Pressurekg/m∙sPa

PrefixAbbreviation Exponential Factor Example megaM Mg = 10 6 g kilok kg = 10 3 g centic g = 10 2 cg millim g = 10 3 mg micro μ g = 10 6 μ g nanon g = 10 9 ng

MASS the amount of matter in an object doesn't change based on location measured on a balance WEIGHT gravitational pull on an object depends on the object's distance from the center of the earth measured on a spring scale

How massive objects are for their size Example: ball of cork vs. ball of lead SI Units: kg/m 3 (useful for gases, not for solids or liquids) Instead: g/cm 3 or g/mL NOTE: Density depends on temperature because substances expand as temperature increases.