Measuring Matter

Metric System / System of International Units (SI) There are seven base units. SI term What it Does Abbreviation Meter for length m Kilogram for mass; applied kg to weight in every- day terms Kelvin temperature K Second time s Ampere electric current A Candela luminous intensity cd Mole amount of substance mol In 1960, the International Committee on Weight and Measures embraced a modern version of the metric system called System of International Units. Its abbreviation is SI. This abbreviation is used in all countries there are no other ways to abbreviate SI. It is also important to know that SI is just another name for the metric system and that the two are the same. There are seven base units of the metric system.

Why use Metric It is simple: it only uses 3 base units of measure. Meter: Length Gram: mass Liter: capacity It is simple: uses a base of 10 The simplicity of the metric system stems from the fact that there is only one unit of measurement (or base unit) for each type of quantity measured (length, mass, etc.). The three most common base units in the metric system are the meter, gram, and liter.

English Units / US Customary Units

Mass A measure of how much matter is in an object. http://www.youtube.com/watch?v=BAf6HoVK6JI

Weight or Mass? ~Weight is a measure of the force of gravity on you. ~On Earth, all objects are attracted downward by Earth’s Gravity. ~Other planets, the force of gravity maybe more or less. ~On Earth everyday life, weight can be useful in measuring matter of an object. ~Scientist rely on the measurement of mass rather than weight. ~Weight can change depending upon location (gravity)

Volume The amount of space that matter occupies. All forms of matter have volume. Finding volume: Volume = Length x Width x Height When you multiply the three measurements, you must multiply the units as well as the numbers. 2 x 2x 2= 2(3) 2cm x 2cm x 2cm = 8cm3

Volume cm3 is Cubic Centimeter How can you measure the volume of an irregular shape, Put the object in a graduated cylinder containing water and measure the change in volume of the water. http://www.youtube.com/watch?v=GhuDEgdO774

Density Substances may have the same mass but don’t fill the same volume. density is the measurement of how much mass is contained in a given volume. To calculate density: Density = Mass volume A unit of density is always a unit of mass. Units of density written: g/cm3 or g/mL http://www.youtube.com/watch?v=BB-SzaZC-Sw