Stating a Measurement In every measurement there is a  Number followed by a  Unit from a measuring device

International System of Units (SI) adopted in 1960 seven base units which all others can be derived m, kg, K, s, mol, cd, A

SI measurement Le Système international d'unités Le Système international d'unités The only countries that have not officially adopted SI are Liberia (in western Africa) and Myanmar (a.k.a. Burma, in SE Asia), but now these are reportedly using metric regularly The only countries that have not officially adopted SI are Liberia (in western Africa) and Myanmar (a.k.a. Burma, in SE Asia), but now these are reportedly using metric regularly Metrication is a process that does not happen all at once, but is rather a process that happens over time. Metrication is a process that does not happen all at once, but is rather a process that happens over time. Among countries with non- metric usage, the U.S. is the only country significantly holding out. The U.S. officially adopted SI in Among countries with non- metric usage, the U.S. is the only country significantly holding out. The U.S. officially adopted SI in Information from U.S. Metric Association

Common Metric Prefixes

properties are that it has: mass: amount of matter (atoms) in an object volume: amount of space an object takes up density: the mass per unit volume of an object Matter What some things that are not matter?

Length a linear measurement meter (m) common units- cm, m, km

Volume space occupied by a sample of matter cubic meter (m 3 ) but we use the non SI unit liter (L) most of the time instead common units- L, ml, cm 3, µL should be measured at 0 °C

Mass this in NOT weight measures the quantity of matter kilogram (kg) common units- kg, g, mg, µg

Temperature measures kinetic energy of particles kelvin (K) common units are K and °C Anders Celsius Lord Kelvin (William Thomson) Kelvin = 1 degree Celsius Notice that 1 Kelvin = 1 degree Celsius

Learning Check Match L) length M) mass V) volume ____ A. A bag of tomatoes is 4.6 kg. ____ B. A person is 2.0 m tall. ____ C. A medication contains 0.50 g Aspirin. ____ D. A bottle contains 1.5 L of water. M L M V

Density an intensive or intrinsic property of matter the ratio of an object’s mass to its volume depends on only on the substance, NOT ON THE SIZE of the substance as temperature increases, density normally decreases (thermal expansion) Back to the Future “Your are my density” clip. Back to the Future “Your are my density” clip

Density D = density M = mass V = volume D = M/V

Example problem A piece of lead has a mass of 56.4 g and a volume of 5.3 cm 3. Calculate its density. M= 56.4 g D=M/V V= 5.3 cm 3 given formula set up problem answer w/ unit of measurement cm 3 is same as ml so sometimes see g/ml 56.4g/5.3 cm 3 11 g/cm 3

Mercury 13.6 g/cm g/cm 3 Aluminum 2.7 g/cm 3 Platinum