Grade 9 Science
Quantitative Physical Properties
Many physical properties of substances can be MEASURED to provide exact information about them:
Length:
base unit:
Mass:
base unit:
Volume:
base unit: solids liquids
Density:
base unit: solids liquids
Fixed Points:
base unit:
Quantitative observations are always reported using the SI system, and must include both a magnitude (the number) and a unit. Prefixes are used when measuring very small or very large amounts.
Example:
Some quantitative physical properties never change despite the amount of the substance present. These are called CHARACTERISTIC PHYSICAL PROPERTIES.
Here are the prefixes used in the metric system. The most commonly used ones are shown in bold:
Prefix Symbol Value
tera T 1 000 000 000 000
giga G 1 000 000 000
mega M 1 000 000
kilo k 1 000
hecto h 100
deca da 10
(none) (none) 1 – base unit
deci d 0.1
centi c 0.01
milli m 0.001
micro m 0.000 001
nano n 0.000 000 001
pico p 0.000 000 000 001
Conversions can be done systematically by using a conversion ladder:
Example:
10 g = ______mg
12.36 dm = ______km
13.2 cL = ______hL
Measuring Volume:
Regular-Shaped Objects:
The volume of cubes, cylinders, cones, etc. can be found using a ruler and a formula.
Example:
Irregular-Shaped Objects:
Archimedes showed that all objects displace an equal volume of water when they are submerged in water. An overflow can is used to measure the volume of liquid displaced.
Liquids:
Volume of a liquid is measured using a graduated cylinder. These come in all shapes and sizes. Two things must be noted when using a graduated cylinder:
1) Always measure from the bottom of the meniscus.
2) Always note the scale of the markings on the graduated cylinder.
Example:
A VERY IMPORTANT CONVERSION TO REMEMBER IS: