D = m/v (g/cm 3 ) Mass usually expressed in grams Volume
usually expressed in cm 3 or liters, etc.
Slide 3
Density = amount of matter per unit volume Density is the ratio
of mass to volume If the volume stays the same and the mass
increases... the density will increase If the mass stays the same
and the volume increases... The density will decrease
Slide 4
M D X V Density = MVMV Volume = MDMD Mass = D x VD x V
Slide 5
OR
Slide 6
How close the atoms or molecules are to eachother More than
heaviness - density includes how much space an object takes up!!
All substances have density including liquids, solids, and gases
Density is the measure of the compactness of a material
Slide 7
Slide 8
When using our calculators we must determine the correct
answer; our calculators are mindless drones and dont know the
correct answer. There are 2 different types of numbers Exact
Measured Exact numbers are infinitely important Measured number =
they are measured with a measuring device (name all 4) so these
numbers have ERROR. When you use your calculator your answer can
only be as accurate as your worst measurementDoohoo Chapter Two
8
Slide 9
9 An exact number is obtained when you count objects or use a
defined relationship. Counting objects are always exact 2 soccer
balls 4 pizzas Exact relationships, predefined values, not measured
1 foot = 12 inches 1 meter = 100 cm For instance is 1 foot =
12.000000000001 inches? No 1 ft is EXACTLY 12 inches.
Slide 10
10 A. Exact numbers are obtained by 1. using a measuring tool
2. counting 3. definition B. Measured numbers are obtained by 1.
using a measuring tool 2. counting 3. definition
Slide 11
11 A. Exact numbers are obtained by 2. counting 3. definition
B. Measured numbers are obtained by 1. using a measuring tool
Slide 12
12 Classify each of the following as an exact or a measured
number. 1 yard = 3 feet The diameter of a red blood cell is 6 x 10
-4 cm. There are 6 hats on the shelf. Gold melts at 1064C.
Slide 13
13 Classify each of the following as an exact (1) or a
measured(2) number. This is a defined relationship. A measuring
tool is used to determine length. The number of hats is obtained by
counting. A measuring tool is required.
Slide 14
Every experimental measurement has a degree of uncertainty. The
volume, V, at right is certain in the 10s place, 10mL