3-1 Notes – Density Chapter 3 Lesson 1. Density Which would have more mass? It depends on BOTH...

3-1 Notes – Density3-1 Notes – Density

Chapter 3Chapter 3

Lesson 1Lesson 1

DensityDensity

Which would have more mass?Which would have more mass?

It depends on BOTH the size of the object AND the material contained inside.

DensityDensity

Density is the amount of mass per unit Density is the amount of mass per unit volume of a material.volume of a material.

D = m V

DensityDensity

Matter is made of atoms which are Matter is made of atoms which are particles that have mass.particles that have mass.

DensityDensity

Density depends on mass AND the Density depends on mass AND the number of particles packed into a given number of particles packed into a given volume.volume.

DensityDensity

DensityDensity

The volume of air has fewer particles, thus The volume of air has fewer particles, thus less mass than the less mass than the samesame volume of water. volume of water.

Thus, the density of air is Thus, the density of air is lessless than the than the density of water.density of water.

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DensityDensity

D = m

VD – density, the unit is g / cm3 (solids) or g / mL (liquids)m – mass, the unit is gV – volume, the unit is cm3 (solids) or mL (liquids)

DensityDensity

Density depends on the material an object Density depends on the material an object is made from, NOT its size.is made from, NOT its size.

DensityDensity

An entire chocolate bar will have the same An entire chocolate bar will have the same density as just one piece. It’s all made density as just one piece. It’s all made from the same material – chocolate.from the same material – chocolate.

DensityDensity

Density depends on the mass of the Density depends on the mass of the particlesparticles. (more mass = more density). (more mass = more density)

DensityDensity

Density depends on the distance between Density depends on the distance between particles. (more distance = less density)particles. (more distance = less density)

DensityDensity

Gases are usually less dense than solids Gases are usually less dense than solids or liquids because particles are far apart.or liquids because particles are far apart.

DensityDensity

DensityDensity To make something less dense, you can To make something less dense, you can

decreasedecrease the the massmass

oror

increaseincrease the the volumevolume of an object. of an object.

DensityDensity

A solid steel ball sinks in water, but that A solid steel ball sinks in water, but that same mass of steel made into a curved same mass of steel made into a curved hull of a boat will float – the shape of the hull of a boat will float – the shape of the hull causes it to displace a greater volume hull causes it to displace a greater volume of water than a solid ball.of water than a solid ball.

DensityDensity

DensityDensity

It was the cold temperature that made the It was the cold temperature that made the iron more brittle when it struck the iceberg. iron more brittle when it struck the iceberg.

The water that leaked in canceled out the The water that leaked in canceled out the less dense air inside the boat’s hull. less dense air inside the boat’s hull.

The density of iron guaranteed that it would The density of iron guaranteed that it would sink.sink.

Measuring DensityMeasuring Density

1.1. Measure its mass.Measure its mass.

2.2. Measure its volume.Measure its volume.

3.3. Divide its mass by its volume.Divide its mass by its volume.

Measuring Measuring MassMass

For a solid, place it directly on the balance.For a solid, place it directly on the balance.

Measuring Measuring MassMass

For a liquid:For a liquid:

1.1. Measure the empty container.Measure the empty container.

2.2. Measure the container AND liquid.Measure the container AND liquid.

3.3. Subtract the container from the total mass.Subtract the container from the total mass.

Measuring Measuring VolumeVolume

For a liquid, use a graduated For a liquid, use a graduated cylinder.cylinder.

Measuring Measuring VolumeVolume For a regular solid (all sides are rectangles):For a regular solid (all sides are rectangles):

1.1. Measure its length, width, height.Measure its length, width, height.

2.2. Multiply all 3 numbers together.Multiply all 3 numbers together.


For an irregular solid, you have to use the For an irregular solid, you have to use the ““displacementdisplacement” method.” method.


1.1. Record the volume of water in a graduated Record the volume of water in a graduated cylinder.cylinder.


2.2. Place the object CAREFULLY (without Place the object CAREFULLY (without splashing) into the graduated cylinder, and splashing) into the graduated cylinder, and record the new volume.record the new volume.


3.3. Subtract the volume of the water from the Subtract the volume of the water from the combined volume. Then you know the combined volume. Then you know the volume of volume of justjust the object. the object.


What is the volume What is the volume

of the hammer?of the hammer?

Initial volume =Initial volume =

Final volume =Final volume =

65 mL65 mL

69 mL69 mL

69mL69mL

- 65 mL- 65 mL

4 mL4 mL

Density is a Physical PropertyDensity is a Physical Property

A physical property is something you can A physical property is something you can measure without changing the composition measure without changing the composition of the material.of the material.

When you measure an object’s mass and When you measure an object’s mass and volume, you don’t change it into something volume, you don’t change it into something else.else.

Density equals ____ divided by volume.

A force

B matter

C solid

D mass

3.1 Density

Density ____ as the distance between particles in an object ____.

A increases; decreases

B increases; increases

C decreases; decreases

D none of the above

3.1 Density

Calculate the volume of a rock that has a mass of 12 g and a density of 3 g/cm3.

A 9 cm3

B 15 cm3

C 4 cm3

D 4 cm

3.1 Density

Gold has a density of 19.3 g/cm3. What is the volume of 19.3 g of gold?

A 19.3 cm3

B 5 g/cm3

C 15 g/cm3

D 1 cm3

Density is mass per unit ____.

A force

B matter

C pressure

D volume

SCI 8.a

A 15g object is placed in a graduated cylinder of water. The water level is at 24 ml. When the object is removed, the water level is at 19 ml. What is the density of the object?

A 5 g/cm3

B 4 g/cm3

C 3 g/cm3

D 19 g/cm3

SCI 8.b

3-1 Notes – Density Chapter 3 Lesson 1. Density Which would have more mass? It depends on BOTH...

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