Section 2: Measuring Matter

Chapter 1: Introduction to Matter

WeightMeasure of the force of gravity on you.Changes depending on location.

e.g. An object weighs less on the moon than it does on Earth because the force of gravity is weaker on the moon than it is on Earth.

Physical property

MassMeasurement of the amount of matter in

the object.Does not change with location or the force of

gravity.Preferred measure of matter over weight.Physical propertyTool: triple beam balanceUnits

International System of Units (SI) unit of mass is the kilogram (kg).

Also commonly measured in grams (g)1 kg = 1,000 g1 g = 0.001 kg

Checkpoint 1What is the difference between mass and

weight?

Checkpoint 1What is the difference between mass and

weight?Weight changes based on the force of

gravity; mass is constant.

VolumeAmount of space that matter occupies.Units: liter (L), milliliter (mL), and cubic centimeter (cm3)

1 L = 1,000 mL1 mL = 0.001 L1 mL = 1 cm3

Finding the volume of liquids: use a graduated cylinderCalculating the volume of regular solids: use a ruler to

measure the length, width and heightVolume = L x W x HUnits = cm x cm x cm = cm3

Calculating the volume of irregular solids: submerge the object in water in a graduated cylinder; the water level will rise by an amount equal to the volume of the object in mL (displacement method)

Physical property

Using a Graduated CylinderMeniscus: concave surface of a liquid

resulting from surface tension.Should always measure a liquid in a

graduated cylinder from the bottom of the meniscus.

Graduated cylinders with smaller gradations are more accurate.

In order to report the correct number of significant digits, you should estimate one additional digit beyond the gradation increment.

Volume = 43.0 mL

Volume of water = 4.80 mL Volume of dinosaur = 0.80 mLVolume of water + dinosaur = 5.60 mL

Checkpoint 2What is the volume of the liquid shown

below?

Checkpoint 2What is the volume of the liquid shown

below?73.0 mL

DensityMeasurement of how much mass

of a substance is contained in a given volume.

D = m/vUnits: g/mL or g/cm3

Objects with a greater density will sink; objects with a lesser density will rise.

Physical propertyIntrinsic/Intensive property (the same

for a given substance regardless of size, shape, or amount; e.g., water always has a density of 1 g/ml)

Can be used to identify and classify matter.

Checkpoint 3The mass of an object is 10 grams and its

volume is 5 cm3. What is the object’s density?

Checkpoint 3The mass of an object is 10 grams and its

volume is 5 cm3. What is the object’s density?

D = m/v = 10 g/5 cm3 = 2 g/cm3

Post-lesson Quiz1. Which of the following tools are used to

measure mass?a. graduated cylinderb. rulerc. triple beam balanced. thermometer

Post-lesson Quiz2. Which of the following tools are used to

measure the volume of liquids?a. graduated cylinderb. rulerc. triple beam balanced. thermometer

Post-lesson Quiz3. An object floats in water. How does the

object compare to the water?a. it is heavierb. it is lighterc. it is denserd. it is less dense

Post-lesson Quiz4. Which of the following is a measure of the

amount of space that matter occupies?a. massb. densityc. volumed. weight

Post-lesson Quiz5. What is the volume of the liquid below?

a. 36.5 mLb. 35 mLc. 37.0 mLd. 36 mL