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

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.

Among countries with nonmetric usage, the U.S. is the *only *

*country significantly holding out*.

The U.S. officially adopted SI in

1866.

Information from U.S.

Metric Association

Common Metric Prefixes

**Matter**

** 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

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**

**Notice that 1 Kelvin = 1 degree Celsius**

Anders Celsius

1701-1744

Lord Kelvin

(William Thomson)

1824-1907

Learning Check

**Match L) length M) mass V) volume**

**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 = M/V**

**D = density**

**M = mass**

**V = volume**

**Example problem**

•

**A piece of lead has a mass of 56.4 g and a volume of 5.3 cm 3 . Calculate its density.**

**given formula set up problem answer w/ unit of measurement**

**M= 56.4 g **

**V= 5.3 cm 3**

**D=M/V 56.4g/5.3 cm 3 11 g/cm 3 cm 3 is same as ml so sometimes see ***g/ml*

Density

mass (g) volume (cm3)

Platinum

Mercury

Aluminum

13.6 g/cm 3 21.5 g/cm 3 2.7 g/cm 3