Measuring Matter
Chapter 1 Section 1
Mrs. Madden
Goals:
 To define mass and accurately measure it with a triple beam balance.
 To explain the difference between weight and mass
 To use the formula to accurately calculate weight
 To define volume
 To practice 3 ways of determining volume
 To define density
 To use the formula to accurately calculate density.
 To use density to identify a substance
Mass
= the amount of matter in an object
= the measure of an object’s ability to resist being moved (inertia)
 Measured with a triple beam balance
 Measured in grams
 Triple beam balance
Weight
= the measure of the force of gravity on an object’s mass
 Gravity changes depending where you are in the universe (on Earth = 9.8 N/kg)
 Measure with spring scale or calculate
Weight = mass * gravity
 Measured in Newtons (N)
 Example: Wt = m * g
Wt = 4kg * 9.8N/kg
Wt= 39.2 N
Wt = m*g
Volume
= the amount of space something takes up
 Tool = graduated cylinder or ruler
 Units = liters, milliliters, or cubic centimeters (cm3)
 1 ml = 1 cm3
 Three ways to measure volume:
1. Liquid = Pour liquid in graduated cylinder
2. Regularly shaped solid:
Volume = L x W x H
Example:
V= L x W x H
V= 10 x 5 x 8
V= 400 cm3
3. Irregularly shaped solid = Water displacement method
Example:
Put rock in 16 ml of water.
Water rises to 23 ml.
What is volume of rock? 7ml
If object is too big for graduated cylinder, use overflow can!
Density
= the mass per unit volume of an object
= the amount of matter in a certain space
= how close particles of matter are packed together
 Density (Big Idea #1) = Calculated by dividing an object’s mass by its volume
 Formula: D= m/v
 Units: g/ml
Density Gizmo main idea…
 Must know that water’s density = 1.0 g/ml
 In water,
 If m<v then density <1 and it will float
 If m>v, then density >1 and it will sink
 Not true for other liquids!!
Density Demo Day concepts we learned…
 More density = sink! Less density = float!
 Even liquids can sink/float in other liquids.
 Even gases can sink/float in other gases.
 Factor that affects density:
 Distance between particles
 Size of particles
Density (Big Idea #1) – D=m/v
Density (Big Idea #2) - Helps us identify and distinguish one kind of matter from another
 Example – Crowns!
Density (Big Idea #3) - A substance has the same density regardless of size!
 Example – Id Lab