Unit 1: Nature of Science. Measurement.
Today most scientists, in almost all countries use the
International System of Units (SI units) as their
system of measurement.
Reason 1: helps scientists share and compare
their data/ results
Reason 2: Another advantage of SI units is all units
are based on the number 10; meaning they are
easily converted from one unit to another
Unit 1: Nature of Science. Measurement.
Length: the distance from one point to another
Basic SI Unit of length: meter
Base unit symbol: m
Tool used to measure length: meter stick
Unit 1: Nature of Science. Measurement.
Volume: The amount of space that matter occupies.
VOLUME OF A LIQUID
Basic SI Unit of liquid volume: liter
Base unit symbol: L
Tool used to measure liquid volume:
graduated cylinder
Unit 1: Nature of Science. Measurement.
Volume of REGULARLY SHAPED SOLID OBJECTS
Basic SI Unit of solid volume: cubic centimeter
Base unit symbol: cm3
Tool used to measure solid volume: meter stick
To calculate solid volume: L x W x H
Unit 1: Nature of Science. Measurement.
Mass: is the amount of matter that something is
made of
Basic SI Unit of mass: gram
Base unit symbol: g
Tool used to measure mass:
triple beam balance
Unit 1: Nature of Science. Measurement.
Volume of an Irregularly Shaped
Object
Basic SI Unit: cubic centimeter
Base unit symbol: cm3
Tool used to measure volume of
irreg. solid: graduated cylinder
Unit 1: Nature of Science. Measurement.
Water Displacement method:
Volume of liquid after object has been submerged
- Original Volume of liquid in grad. Cylinder
Answer is volume of irregular solid object (cm3)
Dora Example
48 mL
-44 mL
4cm3
***BECAUSE 1mL = 1cm3
Unit 1: Nature of Science. Measurement.
Weight: is a measure of the force of gravity on an
object
Basic SI Unit of weight: Newton
Base unit symbol: N
Tool used to measure weight: spring scale
Unit 1: Nature of Science. Measurement.
Mass vs. Weight
Mass DOES NOT change with location, weight DOES!
Unit 1: Nature of Science. Measurement.
Temperature: is a measure of how hot (or
cold) something is. Specifically, the measure
of average kinetic energy of the particles in
the object.
Basic SI Unit of temperature:
Degrees Celsius
Base unit symbol: °C
Tool used to measure temperature: thermometer
Unit 1: Nature of Science. Measurement.
Time: the measure of a passing interval, from one
event to another
Basic SI Unit of time:
second
Base unit symbol: s
Tool used to measure
time: stopwatch
Unit 1: Nature of Science. Measurement.
Density the amount of “stuff” in a particular space
- The density of room temp. water is 1 gram/ cm3
- An object will SINK in water if an objects density
is greater than 1 g/cm3.
- An object will FLOAT in water if its density is less
than 1 g/cm3 it will.
- Density = mass
volume
Unit 1: Nature of Science. Measurement.
An objects density does NOT change when it is broken in
half!
The molecules are still packed in the same way, no matter
the size of the sample.
D= m/v
D= 60 g/25cm3
D= 2.4 g/ cm3
D= m/v
D= 120 g/ 50cm3
D= 2.4 g/ cm3
D= m/v
D= 96 g/ 40cm3
D= 2.4 g/ cm3